Previous Year Paper

UPPSC GIC Lecturer Botany 2017 (Previous Year Paper)

Held in 2017

150 questions120 minutes
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Part I (30 questions)

Question 1

Ubol Ratna, royal princess of a country was declared disqualified to contest as the Prime Ministerial candidate by the Election Commission of her country. She belongs to which one of the following countries?

  1. AOption (a)

    Bhutan

  2. BOption (b)

    Nepal

  3. COption (c)

    Thailand

  4. DOption (d)

    None of these

View answer & explanation

Correct answer

Answer: (c)C.

Thailand

Why this answer is correct

The correct answer is - Thailand

Key Points

  • Ubol Ratana is a member of the Thai royal family. She is the eldest daughter of King Bhumibol Adulyadej (Rama IX) and Queen Sirikit of Thailand.
  • The Thai Constitution prohibits members of the royal family from participating in politics. Despite renouncing her royal titles, Ubol Ratana's candidacy was considered a violation of this rule.
  • In 2019, the Election Commission of Thailand disqualified her from running as a candidate for Prime Minister, citing her royal heritage and the constitutional restrictions.
  • This event was widely discussed in Thailand and internationally, as it marked an unprecedented intersection of monarchy and democratic politics in the country.

Additional Information

  • Thai Monarchy
  • The Thai monarchy is a constitutional monarchy, where the King is the head of state but has limited powers under the constitution.
  • The monarchy is highly respected in Thailand, and laws such as lese majeste criminalize criticism of the royal family.
  • Constitutional Provisions
  • The Thai Constitution explicitly bars members of the royal family from engaging in politics to maintain the neutrality of the monarchy.
  • Despite renouncing her titles, Ubol Ratana was still considered part of the royal family under Thai law, leading to her disqualification.
  • Political Context
  • The political landscape in Thailand has been shaped by frequent military coups and political unrest. The royal family is seen as a stabilizing force.
  • Ubol Ratana's decision to contest elections was seen as controversial, as it challenged long-standing norms separating the monarchy from politics.

Question 2

'Ismail Omar Guelleh', was conferred with Padma-Vibhushan in January 2019 by Government of India, is a citizen of which one of the following countries?

  1. AOption (a)

    Ghana

  2. BOption (b)

    Senegal

  3. COption (c)

    Djibouti

  4. DOption (d)

    Togo

View answer & explanation

Correct answer

Answer: (c)C.

Djibouti

Why this answer is correct

The correct answer is - Djibouti

Key Points

  • Ismail Omar Guelleh
  • Ismail Omar Guelleh is the President of Djibouti, serving in office since 1999.
  • He has played a significant role in strengthening India-Djibouti relations, particularly in trade and diplomatic engagements.
  • Padma-Vibhushan Award
  • This is the second-highest civilian award in India, given for exceptional and distinguished service.
  • Guelleh was conferred this award in January 2019 for his contributions to fostering bilateral ties between Djibouti and India.
  • Djibouti's Strategic Importance
  • Djibouti is located in the Horn of Africa and serves as a strategic transit hub for international shipping routes.
  • Its location has been instrumental in India's efforts to enhance its presence in the Indian Ocean Region.

Additional Information

  • India-Africa Relations
  • India has been actively engaging with African nations through initiatives such as the India-Africa Forum Summit.
  • Djibouti has been a key partner for India in the Horn of Africa, especially in areas like maritime security and trade.
  • Recognition of Foreign Leaders
  • India confers civilian awards like the Padma-Vibhushan to foreign leaders who contribute to strengthening bilateral relationships.
  • Other notable foreign awardees include Shinzo Abe of Japan and Vladimir Putin of Russia.
  • Djibouti's Economic Role
  • Djibouti is home to one of the busiest ports in Africa, making it a critical hub for global trade.
  • Its strategic location near the Gulf of Aden has attracted investments from countries like India, China, and the U.S..

Question 3

To strengthen the 'Handlooms and Textile sector' of India, an event 'Artisan Speak' was organised on 28 January, 2019 at which one of the following places?

  1. AOption (a)

    Elephanta Caves

  2. BOption (b)

    Ahmadnagar

  3. COption (c)

    Jaipur

  4. DOption (d)

    Bhimbetka

View answer & explanation

Correct answer

Answer: (a)A.

Elephanta Caves

Why this answer is correct

The correct answer is - Elephanta Caves

Key Points

  • Elephanta Caves
  • The event ‘Artisan Speak’ was held on 28 January 2019 at the iconic Elephanta Caves, a UNESCO World Heritage Site located near Mumbai.
  • The focus of the event was to promote and strengthen India's Handlooms and Textile sector by connecting artisans to markets and enhancing their visibility.
  • It showcased the rich cultural heritage of India, specifically its traditional textiles and craftsmanship.
  • The venue choice highlighted India's commitment to preserving its historic monuments while promoting its crafts industry.

Additional Information

  • Handlooms and Textile Sector
  • India's textile sector is one of the largest in the world, contributing significantly to the country's economy and employment.
  • Government initiatives like ‘Artisan Speak’ aim to empower artisans, improve production quality, and increase global recognition.
  • Key schemes include the National Handloom Development Programme (NHDP) and the Handicrafts Cluster Development Scheme.
  • Elephanta Caves
  • The caves are located on Elephanta Island, approximately 10 kilometers east of the Gateway of India, Mumbai.
  • Known for their rock-cut sculptures and artistic representation of Hindu deities, particularly Lord Shiva.
  • The site reflects India's rich architectural heritage and cultural significance.

Question 4

Match List I with List II and select -the correct answer from the code given below:

List-I(Acid)List-II(Source)
A. Acetic Acid1. Butter
B. Lactic Acid2. Lemon
C. Butyric Acid3. Vinegar
D. Citric Acid4. Milk
  1. AOption (a)

    A-3, B-4, C-2, D-1

  2. BOption (b)

    A-3, B-4, C-1, D-2

  3. COption (c)

    A-4, B-3, C-1, D-2

  4. DOption (d)

    A-1, B-2, C-3, D-4

View answer & explanation

Correct answer

Answer: (b)B.

A-3, B-4, C-1, D-2

Why this answer is correct

The correct answer is - Acetic Acid - Vinegar, Lactic Acid - Milk, Butyric Acid - Butter, Citric Acid - Lemon

Key Points

  • Acetic Acid - Vinegar
  • Acetic acid is commonly found in vinegar, which is used in cooking and food preservation.
  • It is characterized by its sour taste and pungent smell.
  • Lactic Acid - Milk
  • Lactic acid is produced during the fermentation of milk and is responsible for the sour taste in dairy products like yogurt and curd.
  • It is formed by the action of lactic acid bacteria on lactose (milk sugar).
  • Butyric Acid - Butter
  • Butyric acid is found in butter and contributes to its characteristic smell.
  • It is a short-chain fatty acid that occurs naturally in dairy products.
  • Citric Acid - Lemon
  • Citric acid is abundant in lemons and other citrus fruits, giving them their tangy flavor.
  • It plays a key role in metabolism through the citric acid cycle (Krebs cycle).

Additional Information

  • Acetic Acid
  • It is a weak acid with the chemical formula CH₃COOH.
  • It is widely used in food industry, cleaning products, and chemical synthesis.
  • Lactic Acid
  • Its chemical formula is C₃H₆O₃.
  • Lactic acid is also produced in muscles during intense exercise due to anaerobic respiration.
  • Butyric Acid
  • Its chemical formula is C₄H₈O₂.
  • It plays a role in gut health by serving as a fuel for colon cells.
  • Citric Acid
  • Chemical formula: C₆H₈O₇.
  • It is used as a preservative and flavoring agent in food products.

Question 5

Which of the following is not a true Fish?

  1. AOption (a)

    Rat Fish

  2. BOption (b)

    Cat Fish

  3. COption (c)

    Dog Fish

  4. DOption (d)

    Jelly Fish

View answer & explanation

Correct answer

Answer: (d)D.

Jelly Fish

Why this answer is correct

The correct answer is Jelly Fish.

Key Points

  • Jelly Fish is not a true fish because it lacks the basic anatomical features of a fish, such as a backbone, gills (in the vertebrate sense), and scales. It belongs to the phylum Cnidaria and is an invertebrate. Hence, the statement regarding Jelly Fish is correct in the context of the question.
  • Rat Fish, also known as Chimaeras, is indeed a true fish. It belongs to the class Chondrichthyes and is a cartilaginous fish related to sharks and rays. Hence, statement 1 is incorrect as it is a true fish.
  • Cat Fish is a diverse group of ray-finned fish belonging to the order Siluriformes. They are characterized by prominent barbels, which resemble a cat's whiskers, and are considered true teleost fish. Hence, statement 2 is incorrect as it is a true fish.
  • Dog Fish is a type of small shark belonging to the family Squalidae. As a member of the Chondrichthyes class, it possesses a vertebral column made of cartilage and is classified as a true fish. Hence, statement 3 is incorrect as it is a true fish.
  • In biological terms, a true fish must be a vertebrate, possess gills throughout its life, and typically have fins for locomotion. Jelly Fish are composed of 95% water and lack a brain, blood, or a heart.

Additional Information

  • Characteristics of Jelly Fish:
  • Classification: They belong to the kingdom Animalia, phylum Cnidaria, and class Scyphozoa.
  • Features: They exhibit radial symmetry and have a gelatinous body called a medusa. They use specialized stinging cells called nematocysts to capture prey.
  • Habitat: They are found in every ocean, from the surface to the deep sea, and some species even inhabit freshwater.
  • Characteristics of Rat Fish (Chimaeras):
  • Evolution: These fish branched off from sharks nearly 400 million years ago.
  • Location: They are mostly found in temperate ocean waters at depths of up to 2,600 meters.
  • Anatomy: Unlike sharks, their upper jaws are fused to their skulls, and they have permanent grinding tooth plates.
  • Characteristics of Cat Fish:
  • Diversity: There are over 3,000 species of Cat Fish found on every continent except Antarctica.
  • Uses: Many species are of significant importance in aquaculture and as food, such as the Channel Catfish in the United States.
  • Functions: Their barbels contain chemoreceptors used to detect food in murky water.
  • Characteristics of Dog Fish:
  • Scientific Name: The most common species is Squalus acanthias (Spiny Dogfish).
  • Applications: They are frequently used in biological laboratories for dissection due to their Generalized vertebrate anatomy.
  • Data: They have a very long gestation period, lasting about 18 to 24 months, which is one of the longest in the animal kingdom.

Important Points

  • Misleading Common Names: Several aquatic animals have "fish" in their name but are not true fish. Examples include Starfish (an Echinoderm), Silverfish (an Insect), Cuttlefish (a Mollusk), and Whales/Dolphins (Mammals).
  • Taxonomy: True fish are generally categorized into three groups: Agnatha (jawless fish), Chondrichthyes (cartilaginous fish), and Osteichthyes (bony fish).
  • Ecological Role: True fish play a vital role in the aquatic food web, serving as both predators and prey, while invertebrates like Jelly Fish can sometimes cause ecological imbalances through "blooms" caused by climate change and overfishing of their natural predators.

Question 6

During intense exercise, which of the following is produced as a metabolic by-product in the muscles?

  1. AOption (a)

    Glycogen

  2. BOption (b)

    Protein

  3. COption (c)

    Fat

  4. DOption (d)

    Lactic Acid

View answer & explanation

Correct answer

Answer: (d)D.

Lactic Acid

Why this answer is correct

The correct answer is Lactic Acid.

Key Points

  • During intense physical exercise or vigorous activity, the demand for energy in the skeletal muscles increases rapidly, often outstripping the oxygen supply provided by the circulatory system.
  • When oxygen levels are low (a state known as hypoxia), muscle cells switch from aerobic respiration to anaerobic respiration to continue producing Adenosine Triphosphate (ATP).
  • In this anaerobic pathway, glucose undergoes glycolysis to form pyruvate, which is then converted into Lactic Acid (specifically lactate in biological fluids). This metabolic by-product is produced to regenerate NAD+, allowing glycolysis to continue. Hence, the statement regarding Lactic Acid production is correct.
  • The buildup of Lactic Acid in the muscles is a primary cause of the burning sensation and temporary fatigue experienced during high-intensity sprints or weightlifting.
  • While anaerobic respiration is less efficient than aerobic respiration, producing only 2 ATP molecules per glucose molecule, it provides energy at a much faster rate for short bursts of activity.

Additional Information

  • Glycogen:
  • Glycogen is a multibranched polysaccharide that serves as the primary form of energy storage in humans and animals.
  • It is stored mainly in the liver and skeletal muscles. During exercise, it is broken down into glucose to fuel metabolism; therefore, it is a reactant/fuel, not a metabolic by-product.
  • The Cori Cycle:
  • After the cessation of exercise, Lactic Acid is transported through the bloodstream to the liver.
  • In the liver, it is converted back into pyruvate and eventually into glucose through gluconeogenesis. This cycle is essential for preventing lactic acidosis and recycling carbon sources.
  • Muscle Fatigue and DOMS:
  • Contrary to popular belief, Lactic Acid is not the cause of Delayed Onset Muscle Soreness (DOMS), which typically peaks 24 to 48 hours after exercise.
  • DOMS is caused by microscopic tears in the muscle fibers and subsequent inflammation. Lactic Acid is usually cleared from the bloodstream within 1 hour after exercise.
  • Aerobic vs. Anaerobic Metabolism:
  • Aerobic metabolism occurs in the mitochondria and produces carbon dioxide and water as by-products, yielding approximately 36 to 38 ATP.
  • Anaerobic metabolism occurs in the cytoplasm and is the dominant energy system for activities lasting 10 to 90 seconds.

Important Points

  • Proteins and Fats: While proteins and fats are used as macronutrients for energy production (especially during long-duration, low-intensity exercise like marathons), they are not the immediate by-products of anaerobic muscle contraction.
  • Chemical Equation: The chemical formula for Lactic Acid is C3H6O3. In the body, it usually exists as the lactate ion (C3H5O3-).
  • Energy Yield: The fast glycolytic system (anaerobic) provides ATP rapidly but results in the acidification of the muscle environment, which eventually inhibits enzyme activity and muscle contraction.

Question 7

Consider the following statements and select the correct answer from the code given below.

A. Colour blindness occurs more in men than in women.

B. Night blindness occurs in old persons not in young ones.

  1. AOption (a)

    Only A

  2. BOption (b)

    Only B

  3. COption (c)

    A and B both

  4. DOption (d)

    N either A nor B

View answer & explanation

Correct answer

Answer: (a)A.

Only A

Why this answer is correct

The correct answer is Only A.

Key Points

  • Statement A: Colour blindness is a genetic condition that is typically sex-linked and recessive, carried on the X chromosome. Since men have only one X chromosome (XY), they will manifest the condition if that single chromosome carries the mutated gene. Women, however, have two X chromosomes (XX), meaning they only express the condition if both chromosomes are affected; otherwise, they remain carriers. Statistically, colour blindness affects approximately 8% of men compared to only 0.5% of women worldwide. Hence, statement A is correct.
  • Statement B: Night blindness, medically known as Nyctalopia, is a condition where the individual finds it difficult or impossible to see in low light or darkness. It is primarily caused by a Vitamin A deficiency, which affects the production of rhodopsin in the rod cells of the retina. While it can occur in old persons due to cataracts or macular degeneration, it is extremely common in young children and young adults, especially in developing countries where malnutrition is prevalent. Hence, statement B is incorrect.
  • The retina of the human eye contains two types of photoreceptors: cones and rods. Cones are responsible for color vision and function best in bright light, while rods are essential for vision in dim light. Defects in cones lead to colour blindness, whereas impairment of rods leads to night blindness.
  • Colour blindness is mostly congenital (present from birth), meaning the age of the person does not determine its onset. In contrast, night blindness can be acquired at any point in life due to dietary habits, health conditions, or medical treatments.

Additional Information

  • Colour Blindness (Daltonism):
  • Types: The most common form is Red-Green colour blindness, followed by Blue-Yellow colour blindness. The rarest form is Total Colour Blindness (Achromatopsia), where the world is seen in grayscale.
  • Diagnosis: Doctors use the Ishihara Test, which consists of a series of plates (circles) containing dots of different colours and sizes forming numbers or paths.
  • Applications: Understanding this condition is vital for certain professions like pilots, train drivers, and electricians, where colour coding is a matter of safety.
  • Night Blindness (Nyctalopia):
  • Causes: Beyond Vitamin A deficiency, other causes include Retinitis Pigmentosa (a genetic disorder), Glaucoma, Cataracts, and Usher syndrome.
  • Data and Facts: According to the World Health Organization (WHO), Vitamin A deficiency is the leading cause of preventable blindness in children worldwide, affecting millions in Africa and South-East Asia.
  • Functions: The rod cells contain rhodopsin (visual purple). When light strikes this pigment, it bleaches, sending an electrical signal to the brain. Vitamin A is required to regenerate this pigment.

Important Points

  • Genetics of Colour Blindness: If a mother is a carrier and the father has normal vision, there is a 50% chance that a son will be colour blind. A daughter can only be colour blind if her father is colour blind and her mother is at least a carrier.
  • Vitamin A Sources: To prevent night blindness, the Government of India promotes the consumption of Golden Rice, carrots, sweet potatoes, spinach, and animal liver, which are rich in Retinol or Beta-carotene.
  • Legal Guidelines: In India, under the Medical Standards for various government jobs, candidates with colour blindness are often restricted from technical cadres in the Railways and Armed Forces.
  • Treatment: While there is currently no permanent cure for hereditary colour blindness, night blindness caused by malnutrition can often be reversed with therapeutic doses of Vitamin A supplements within a few days or weeks.

Question 8

Consider the following statements and select the correct answer from the code given below :

Assertion (A): Polarisation does not happen in sound waves.

Reason (R): Sound waves are transverse waves.

Code:

  1. AOption (a)

    Both (A) and (R) are true and (R) is the correct explanation of (A).

  2. BOption (b)

    Both (A) and (R) are true, but (R) is not the correct explanation of (A).

  3. COption (c)

    (A) is true, but (R) is false.

  4. DOption (d)

     (A) is false, but (R) is true.

View answer & explanation

Correct answer

Answer: (c)C.

(A) is true, but (R) is false.

Why this answer is correct

The correct answer is (A) is true, but (R) is false..

Key Points

  • Assertion (A) states that polarisation does not happen in sound waves. This is because polarisation is a characteristic property of transverse waves, where the vibrations occur perpendicular to the direction of wave travel. Sound waves in air and most fluids are longitudinal waves, meaning the particles oscillate parallel to the direction of energy transfer. Since longitudinal waves only have one dimension of oscillation, they cannot be restricted to a specific plane. Hence, Assertion (A) is correct.
  • Reason (R) claims that sound waves are transverse waves. In physics, a transverse wave is one where the medium moves at right angles to the direction of the wave, such as light waves or waves on a guitar string. However, sound waves are actually mechanical longitudinal waves that require a medium (solid, liquid, or gas) to travel through compressions and rarefactions. Hence, Reason (R) is incorrect.
  • The phenomenon of polarisation serves as the primary experimental evidence to distinguish between transverse and longitudinal waves. If a wave can be polarised, it must be transverse. Since sound cannot be polarised, it confirms its longitudinal nature in gaseous and liquid media.
  • In solids, sound can occasionally travel as transverse waves (shear waves), but in the general context of physics and standard conditions, sound is treated as a longitudinal wave.

Additional Information

  • Longitudinal Waves: These are waves in which the displacement of the medium is in the same direction as, or the opposite direction to, the direction of propagation of the wave. Sound waves are the most common example. They consist of compressions (high pressure) and rarefactions (low pressure).
  • Transverse Waves: In these waves, the particles of the medium move perpendicular to the direction of the wave's motion. Examples include Electromagnetic waves (like visible light, X-rays, and radio waves) and seismic S-waves. These waves can be polarised using polarisers.
  • Polarisation: This is a property applying to transverse waves that specifies the geometrical orientation of the oscillations. In a transverse wave, the direction of the oscillation is perpendicular to the direction of motion of the wave. A polarising filter (like Polaroid sunglasses) can block oscillations in certain planes while allowing others to pass.
  • Speed of Sound: The speed of sound depends on the temperature and the elasticity of the medium. In dry air at 20 °C (68 °F), the speed of sound is approximately 343 metres per second (1,235 km/h). It travels fastest in solids, slower in liquids, and slowest in gases.
  • Frequency and Audibility: The frequency of sound waves determines their pitch. The audible range for the human ear is typically between 20 Hz and 20,000 Hz (20 kHz). Sound with a frequency below 20 Hz is called infrasound, and above 20 kHz is called ultrasound.

Important Points

  • Medium Requirement: Unlike light waves (which are electromagnetic and can travel through a vacuum), sound waves are mechanical and require a material medium to propagate. Sound cannot travel through outer space.
  • Wave Interactions: Both sound and light undergo reflection, refraction, interference, and diffraction. However, only light (and other transverse waves) can undergo polarisation.
  • Historical Context: The wave theory of light was significantly strengthened when Augustin-Jean Fresnel and Thomas Young demonstrated that light could be polarised, proving it was a transverse wave rather than a longitudinal one like sound.
  • Application of Polarisation: It is used in 3D movies, LCD screens, and stress analysis of plastics. Because sound is longitudinal, these applications do not exist for acoustic waves in the same manner.

Question 9

The Life was originated on the earth about 

  1. AOption (a)

    3.0 billion years ago

  2. BOption (b)

    3.5 billion years ago

  3. COption (c)

    4.0 billion years ago

  4. DOption (d)

    4.5 billion years ago

View answer & explanation

Correct answer

Answer: (b)B.

3.5 billion years ago

Why this answer is correct

The correct answer is 3.5 billion years ago.

Key Points

  • The origin of life on Earth is a complex process that began after the planet's surface cooled sufficiently to allow for the existence of liquid water. Scientists generally agree that life originated approximately 3.5 billion years ago.
  • The earliest direct physical evidence of life consists of microfossils found in 3.5 billion-year-old rocks from Western Australia. These fossils resemble modern-day prokaryotes.
  • Stromatolites, which are mineralized microbial mats formed by cyanobacteria, provide some of the oldest records of life. Some of these formations have been dated back to nearly 3.5 billion years, indicating a thriving microbial ecosystem during the Archaean Eon.
  • The transition from non-living matter to living organisms is known as abiogenesis. It is hypothesized that this occurred through a series of chemical evolutions in the primitive atmosphere of the Earth.
  • While Earth itself formed about 4.54 billion years ago, the first 500 to 700 million years (the Hadean Eon) were likely too volatile for life to survive due to intense volcanic activity and meteorite bombardments.

Additional Information

  • Formation of Earth: The Earth was formed approximately 4.6 billion years ago from a cloud of gas and dust surrounding the young Sun. In its early stages, the atmosphere was reducing, containing methane, ammonia, water vapor, and hydrogen, but almost no free oxygen.
  • Oparin-Haldane Theory: Proposed in the 1920s, this theory suggests that life arose from organic molecules that formed in the "primordial soup" of the early oceans. These molecules were synthesized using energy from lightning and ultraviolet (UV) radiation.
  • The Miller-Urey Experiment: In 1953, Stanley Miller and Harold Urey conducted a landmark experiment that simulated early Earth conditions. They successfully synthesized amino acids, which are the fundamental building blocks of proteins, proving that organic compounds could form spontaneously.
  • Evolutionary Timeline: Following the emergence of unicellular organisms around 3.5 billion years ago, it took nearly 2 billion years for complex eukaryotic cells to appear. Multicellular life began to flourish much later, roughly 600 to 800 million years ago, leading to the Cambrian Explosion.
  • Hydrothermal Vents: Many modern theories suggest that life may have actually originated near deep-sea hydrothermal vents, where heat and mineral-rich water provided the necessary energy for chemosynthesis.

Important Points

  • Biological Signatures: Isotopic evidence (ratios of Carbon-12 to Carbon-13) found in Greenland suggests that biological activity might have existed as early as 3.8 to 4.1 billion years ago, although 3.5 billion years remains the most widely accepted date for confirmed fossil evidence.
  • The Role of RNA: The RNA World Hypothesis suggests that RNA was the first self-replicating molecule, preceding DNA and proteins in the early stages of life's origin.
  • Oxygenation of Atmosphere: Significant oxygen levels did not appear in the atmosphere until about 2.4 billion years ago during the Great Oxidation Event, triggered by the photosynthetic activity of cyanobacteria.

Question 10

Which of the following is the largest island from area point of view in the Indian ocean? 

  1. AOption (a)

    Zanzibar

  2. BOption (b)

    Seychelles

  3. COption (c)

    Madagaskar

  4. DOption (d)

    Mauritius

View answer & explanation

Correct answer

Answer: (c)C.

Madagaskar

Why this answer is correct

The correct answer is Madagascar.

Key Points

  • Madagascar is the largest island in the Indian Ocean and the fourth-largest island in the world, covering an area of approximately 587,041 square kilometers.
  • It is located approximately 400 kilometers off the Southeastern coast of Africa, separated from the mainland by the Mozambique Channel.
  • Geologically, Madagascar is considered a microcontinent because it was part of the Gondwana supercontinent and separated from India about 88 million years ago, allowing its plants and animals to evolve in relative isolation.
  • The island is famous for its mega-biodiversity; more than 90% of its wildlife is endemic, meaning species like lemurs and certain Baobab trees are found nowhere else on Earth.
  • The topography of the island is diverse, featuring a central highland, rainforests along the eastern coast, and dry deciduous forests to the west.

Additional Information

  • Zanzibar: This is an archipelago off the coast of East Africa (part of Tanzania). Its largest island, Unguja, has an area of only about 1,666 square kilometers. It is globally famous as the "Spice Island" for its production of cloves, nutmeg, and cinnamon.
  • Seychelles: An archipelagic country in the Indian Ocean consisting of 115 islands. The total land area is small, roughly 459 square kilometers. Its capital, Victoria, is located on the largest island, Mahé. It is a major tourist destination known for its coral reefs and beaches.
  • Mauritius: A volcanic island nation located east of Madagascar. It has a land area of about 2,040 square kilometers. It is known for its high Human Development Index (HDI) and was the only known habitat of the now-extinct Dodo bird.
  • Indian Ocean: It is the third-largest of the world's five oceanic divisions, covering about 20% of the Earth's water surface. It is bounded by Asia to the north, Africa to the west, and Australia to the east.

Important Points

  • The capital and largest city of Madagascar is Antananarivo, located in the central highlands.
  • The country gained independence from France on June 26, 1960. The official languages spoken are Malagasy and French.
  • Economically, Madagascar is the world's leading producer of natural vanilla, accounting for nearly 80% of the global market.
  • The highest point in Madagascar is Maromokotro, which stands at an elevation of 2,876 meters in the Tsaratanana Massif.
  • In terms of global island rankings, Madagascar follows Greenland, New Guinea, and Borneo in total land area.

Question 11

Which of the following rivers crosses the equator twice in its flow? 

  1. AOption (a)

    Nile

  2. BOption (b)

    Congo

  3. COption (c)

    Niger

  4. DOption (d)

    Amazon

View answer & explanation

Correct answer

Answer: (b)B.

Congo

Why this answer is correct

The correct answer is Congo.

Key Points

  • The Congo River, also known as the Zaire River, is the only major river in the world that crosses the Equator twice during its course. Hence, the statement regarding Congo is correct.
  • It is the second-longest river in Africa, after the Nile, and has the second-largest discharge volume in the world, following the Amazon River.
  • The river flows through the Congo Basin, which houses the world's second-largest rainforest, spanning across several countries including the Democratic Republic of the Congo, Congo Republic, Central African Republic, and others.
  • Its unique path takes it from the Lualaba River (its main headstream) northward across the Equator, then it turns west and curves southward, crossing the Equator a second time before flowing into the Atlantic Ocean.
  • The Congo River is also recognized as the deepest river in the world, with measured depths reaching up to 220 meters (720 feet) in certain sections.

Additional Information

  • Nile River:
  • Located in Northeastern Africa, it is traditionally considered the longest river in the world with a length of approximately 6,650 km.
  • It flows northward and passes through 11 countries, eventually emptying into the Mediterranean Sea. It crosses the Equator only once in its upper reaches near Lake Victoria. Hence, the statement regarding the Nile is incorrect.
  • Amazon River:
  • Situated in South America, it is the largest river by discharge volume and the second-longest river in the world (approx. 6,400 km).
  • The Amazon flows through Peru, Colombia, and Brazil. While its mouth is very close to the Equator, the river itself does not cross the Equator twice. Hence, the statement regarding the Amazon is incorrect.
  • Niger River:
  • This is the third-longest river in Africa (approx. 4,180 km) and the principal river of West Africa.
  • It has an unusual boomerang shape, flowing away from the sea into the Sahara Desert before turning southeast towards the Gulf of Guinea. It does not cross the Equator at any point. Hence, the statement regarding the Niger is incorrect.
  • Limpopo River:
  • Located in Southern Africa, this river is famous for crossing the Tropic of Capricorn twice, rather than the Equator.

Important Points

  • Hydroelectric Potential: The Congo River possesses the highest hydroelectric potential of any river system in the world due to its massive water volume and steep drops, such as the Inga Falls.
  • Economic Importance: It serves as a vital navigation route in Central Africa, as roads and railways are often difficult to maintain in the dense tropical rainforest.
  • Flora and Fauna: The river basin supports incredible biodiversity, including endemic species of fish and the Bonobo (pygmy chimpanzee), found only in the forests of the Democratic Republic of the Congo.
  • Historical Context: Exploration of the river was famously documented by Henry Morton Stanley in the late 19th century, which opened the region to European colonization.

Question 12

In which of the following cities, the Indian Institute of Remote Sensing (IIRS) is located? 

  1. AOption (a)

    Dehradun

  2. BOption (b)

    Ahmedabad

  3. COption (c)

    Hyderabad

  4. DOption (d)

    Nagpur

View answer & explanation

Correct answer

Answer: (a)A.

Dehradun

Why this answer is correct

The correct answer is Dehradun.

Key Points

  • The Indian Institute of Remote Sensing (IIRS) is a premier institute for capacity building and research located in Dehradun, the capital city of Uttarakhand, India.
  • It was established in the year 1966 as the Indian Photo-interpretation Institute (IPI), following the pattern of the International Institute for Geo-Information Science and Earth Observation (ITC), The Netherlands.
  • The institute functions as a constituent unit of the Indian Space Research Organisation (ISRO), which operates under the Department of Space, Government of India.
  • The primary function of IIRS is to provide training and education to professionals and students in the fields of Remote Sensing, Geoinformatics, and Global Positioning System (GPS) technology.
  • The institute offers various academic programs, including M.Tech, M.Sc., Post Graduate Diploma, and certificate courses, catering to both national and international participants from Asia and Africa.
  • Its core applications involve the use of satellite data for natural resource management, disaster management, and environmental monitoring.

Additional Information

  • National Remote Sensing Centre (NRSC):
  • Located in Hyderabad, Telangana, this centre is responsible for remote sensing satellite data acquisition, processing, and dissemination.
  • It plays a vital role in disaster management support through the Decision Support Centre and manages the Ground Station for IRS satellites at Shadnagar.
  • Space Applications Centre (SAC):
  • Situated in Ahmedabad, Gujarat, this is a major research and development centre of ISRO.
  • It focuses on the design and development of payloads (spaceborne instruments) for communications, meteorology, and remote sensing satellites.
  • Regional Remote Sensing Centre (RRSC):
  • The RRSC-Central is located in Nagpur, Maharashtra. There are five such regional centres across India, including Bengaluru, Jodhpur, Kolkata, and New Delhi.
  • These centres provide digital image processing and Geographic Information System (GIS) based solutions for regional planning and resource mapping.
  • Indian Space Research Organisation (ISRO):
  • Founded on 15 August 1969, it is headquartered in Bengaluru. It succeeded the Indian National Committee for Space Research (INCOSPAR).
  • ISRO is known for its cost-effective missions like Mars Orbiter Mission (Mangalyaan), Chandrayaan-3, and the Polar Satellite Launch Vehicle (PSLV).

Important Points

  • Remote Sensing: This refers to the process of detecting and monitoring the physical characteristics of an area by measuring its reflected and emitted radiation from a distance, typically using satellites or aircraft.
  • Geoinformatics: It is the science and technology dealing with the structure and character of spatial information, its capture, its classification, and its storage.
  • CSSTEAP: The Centre for Space Science and Technology Education in Asia and the Pacific, affiliated with the United Nations, is also hosted at the IIRS campus in Dehradun to promote international cooperation.
  • Data Products: IIRS and NRSC collaborate to provide high-resolution topographic maps and thematic maps used in urban planning and agriculture.

Question 13

In which year the Organization of Petroleum Exporting Countries (OPEC) was created?

  1. AOption (a)

    1955

  2. BOption (b)

    1960

  3. COption (c)

    1965

  4. DOption (d)

    1970

View answer & explanation

Correct answer

Answer: (b)B.

1960

Why this answer is correct

The correct answer is 1960.

Key Points

  • The Organization of Petroleum Exporting Countries (OPEC) was created at the Baghdad Conference held in Iraq. The conference took place between September 10 and 14, 1960.
  • The organization was founded by five core oil-producing nations: Iran, Iraq, Kuwait, Saudi Arabia, and Venezuela. These nations aimed to exercise sovereign rights over their natural resources.
  • The primary function of OPEC is to coordinate and unify the petroleum policies of its member countries to ensure the stabilization of oil prices in international markets. This statement confirms that the year of creation is 1960.
  • It was established as a permanent intergovernmental organization to provide an efficient, economic, and regular supply of petroleum to consuming nations and to ensure a fair return on capital for investors in the industry.
  • The creation of OPEC in 1960 marked a significant shift in the global energy landscape, as it challenged the dominance of the "Seven Sisters" multinational oil companies that controlled oil prices at that time.

Additional Information

  • Headquarters Location: Initially, the OPEC headquarters were established in Geneva, Switzerland. However, they were moved to Vienna, Austria, on September 1, 1965.
  • Membership Expansion: Since its founding in 1960, several other nations have joined the organization, including Libya (1962), United Arab Emirates (1967), Algeria (1969), Nigeria (1971), and Gabon (1975).
  • OPEC+ Collaboration: In December 2016, OPEC formed an alliance with 10 non-OPEC oil-producing countries, including Russia, known as OPEC+, to further regulate global oil supply and prices.
  • Statutory Organs: The organization operates through three main bodies: the Conference (the supreme authority), the Board of Governors, and the Secretariat (based in Vienna).
  • Economic Impact: OPEC members collectively hold approximately 80% of the world's proven crude oil reserves, which allows the organization to have a profound impact on global inflation and economic growth through its production quotas.

Important Points

  • Legal Recognition: OPEC is registered with the United Nations Secretariat under Article 102 of the UN Charter, following Registration No. 6363.
  • Secretary General: The Secretariat is headed by a Secretary General, who serves as the organization's chief executive officer. The designation involves overseeing the daily administrative operations and implementing Conference decisions.
  • Oil Price Shocks: Historically, OPEC gained global prominence during the 1973 oil crisis when it implemented an oil embargo, demonstrating the organization's immense geopolitical power.
  • Production Data: According to recent surveys and reports, OPEC countries produce roughly 40% of the world's total crude oil, making their numerical value of exports critical for energy security in many developed and developing countries.

Question 14

Under which Article of the Indian Constitution Chairman and members of UPSC can be removed from their office? 

  1. AOption (a)

    Article-320

  2. BOption (b)

    Article-315

  3. COption (c)

    Article-322

  4. DOption (d)

    Article-317

View answer & explanation

Correct answer

Answer: (d)D.

Article-317

Why this answer is correct

The correct answer is Article-317.

Key Points

  • Article 317 of the Constitution of India provides the detailed procedure for the removal and suspension of a member of a Public Service Commission. According to this article, the Chairman or any other member of the Union Public Service Commission (UPSC) can only be removed from their office by an order of the President. Hence, the correct answer is Article-317.
  • The primary ground for removal mentioned in this article is misbehaviour. However, for removal on this ground, the President must refer the matter to the Supreme Court of India for an inquiry. If the Supreme Court, after following the procedure prescribed under Article 145, reports that the person ought to be removed, then the President can issue the removal order.
  • The President also has the authority to remove the Chairman or any other member without a Supreme Court inquiry if the individual is adjudged an insolvent, engages during their term of office in any paid employment outside the duties of their office, or is, in the opinion of the President, unfit to continue in office by reason of infirmity of mind or body.
  • During the period of inquiry by the Supreme Court, the President has the power to suspend the Chairman or member of the Union Commission until the final report is submitted and orders are passed.

Additional Information

  • Article-315:
  • This article mandates the establishment of a Public Service Commission for the Union and a Public Service Commission for each State.
  • It also allows two or more States to agree that there shall be one Joint State Public Service Commission (JSPSC) for that group of States, which is created by an Act of Parliament. Hence, statement regarding Article-315 is related to establishment, not removal.
  • Article-320:
  • This article enumerates the various functions of the Public Service Commissions.
  • Key functions include conducting examinations for appointments to the services of the Union and the States, and being consulted on matters relating to methods of recruitment, promotions, and disciplinary actions. Hence, statement regarding Article-320 is related to functions, not removal.
  • Article-322:
  • This article specifies the expenses of the Public Service Commissions.
  • It states that the expenses of the Union Commission, including salaries, allowances, and pensions payable to members and staff, shall be charged on the Consolidated Fund of India. Hence, statement regarding Article-322 is related to financial expenses, not removal.

Important Points

  • Constitutional Framework: The UPSC is an independent constitutional body under Part XIV of the Constitution of India, covering Articles 315 to 323.
  • Composition and Tenure: The Commission usually consists of 9 to 11 members, including the Chairman. They are appointed by the President of India for a term of six years or until they attain the age of 65 years, whichever is earlier.
  • Independence: To maintain the impartiality of the Commission, the Chairman of the UPSC is ineligible for any further employment under the Government of India or any State Government after retirement.
  • Conditions of Service: Under Article 318, the President is empowered to determine the number of members of the Commission and their conditions of service. However, these conditions cannot be varied to their disadvantage after their appointment.

Question 15

The President of India submits his resignation letter to whom among the following? 

  1. AOption (a)

    The Chief Justice of India.

  2. BOption (b)

     The Speaker of Lok-Sabha.

  3. COption (c)

     The Prime Minister of India.

  4. DOption (d)

     The Vice-President of India and Communicate to Speaker of Lok Sabha.

View answer & explanation

Correct answer

Answer: (d)D.

 The Vice-President of India and Communicate to Speaker of Lok Sabha.

Why this answer is correct

The correct answer is The Vice-President of India and Communicate to Speaker of Lok Sabha.

Key Points

  • According to Article 56(1)(a) of the Constitution of India, the President may, by writing under his hand addressed to the Vice-President, resign his office.
  • Article 56(2) further mandates that any resignation addressed to the Vice-President under clause (a) of the proviso to clause (1) shall forthwith be communicated by him to the Speaker of the Lok Sabha. Hence, statement 4 is correct.
  • The Chief Justice of India is responsible for administering the Oath or Affirmation to the President as per Article 60, but they do not receive the resignation letter. Hence, statement 1 is incorrect.
  • The Speaker of the Lok Sabha is the presiding officer of the lower house. While they must be informed of the resignation by the Vice-President, the resignation letter itself is not directly submitted to them. Hence, statement 2 is incorrect.
  • The Prime Minister of India is the head of the Council of Ministers. There is no constitutional provision that requires the President to submit a resignation letter to the Prime Minister. Hence, statement 3 is incorrect.

Additional Information

  • Article 52 to 62 of the Indian Constitution deal with the President of India. The President is the Head of State and the First Citizen of India.
  • Qualifications for Election (Article 58): To be eligible for election as President, a person must be a citizen of India, have completed the age of 35 years, and be qualified for election as a member of the Lok Sabha.
  • Term of Office (Article 56): The President holds office for a term of 5 years from the date on which he enters his office. However, he can continue to hold office beyond his term until his successor enters upon his office.
  • Election Process (Article 54): The President is elected by an Electoral College consisting of the elected members of both Houses of Parliament and the elected members of the Legislative Assemblies of the States and Union Territories of Delhi and Puducherry.
  • Impeachment (Article 61): The President can be removed from office before the expiry of the term through the process of impeachment for the "violation of the Constitution."

Important Points

  • In the event of a vacancy in the office of the President due to death, resignation, or removal, the Vice-President acts as the President until a new President is elected.
  • If the office of the Vice-President is also vacant, the Chief Justice of India (or in his absence, the senior-most Judge of the Supreme Court) discharges the functions of the President.
  • An election to fill a vacancy in the office of President occurring by reason of death, resignation, or removal must be held as soon as possible, and in no case later than six months from the date of occurrence of the vacancy.
  • The President is eligible for re-election to that office under Article 57 of the Constitution, with no limit on the number of terms a person can serve.

Question 16

'India Innovation Index' has been mainly launched by which one of the following organizations? 

  1. AOption (a)

    NITI Aayog

  2. BOption (b)

    SEBI

  3. COption (c)

    RBI

  4. DOption (d)

    CSO

View answer & explanation

Correct answer

Answer: (a)A.

NITI Aayog

Why this answer is correct

The correct answer is NITI Aayog.

Key Points

  • The India Innovation Index is a comprehensive tool developed by NITI Aayog (National Institution for Transforming India) in collaboration with the Institute for Competitiveness. Hence, the statement regarding NITI Aayog is correct.
  • The primary objective of the index is to rank Indian states and union territories based on their relative performance in supporting innovation, thereby fostering a spirit of competitive federalism.
  • The framework of the index is based on seven pillars, which are further divided into Enablers and Performance dimensions. The Enablers include Human Capital, Investment, Knowledge Workers, Business Environment, and Safety and Legal Environment.
  • The Performance dimension measures Knowledge Output and Knowledge Diffusion, providing a holistic view of the innovation landscape across different regions of India.
  • The third edition of the India Innovation Index (2021) was released in July 2022. In this edition, Karnataka continued to hold the first rank in the Major States category, while Manipur topped the North East and Hill States category, and Chandigarh ranked first among Union Territories and City-States.

Additional Information

  • NITI Aayog: Established on January 1, 2015, it replaced the Planning Commission. It functions as the premier policy think tank of the Government of India, providing both directional and policy inputs. The Prime Minister is the Ex-officio Chairperson, and the Vice-Chairperson is appointed by the Prime Minister.
  • SEBI (Securities and Exchange Board of India): It is the regulatory body for the securities and commodity market in India under the ownership of the Ministry of Finance. It was established on April 12, 1988, and given statutory powers on January 30, 1992, through the SEBI Act, 1992. It is not involved in launching the Innovation Index. Hence, this option is incorrect.
  • RBI (Reserve Bank of India): India's central bank and regulatory body responsible for regulation of the Indian banking system. It was established on April 1, 1935, under the Reserve Bank of India Act, 1934. Its headquarters are in Mumbai. Its main functions include monetary policy and currency issuance. Hence, this option is incorrect.
  • CSO (Central Statistical Office): Now merged with the National Sample Survey Office (NSSO) to form the National Statistical Office (NSO), it functions under the Ministry of Statistics and Programme Implementation (MoSPI). It is responsible for the coordination of statistical activities and maintaining statistical standards, including the calculation of GDP. Hence, this option is incorrect.

Important Points

  • The India Innovation Index is inspired by the Global Innovation Index (GII), which is published annually by the World Intellectual Property Organization (WIPO).
  • The index uses a total of 66 indicators to assess the innovation performance, compared to 36 indicators used in the first edition (2019), showing an increase in the depth of data analysis.
  • The Government of India uses these reports to identify specific strengths and weaknesses at the state level, allowing for targeted policy interventions to improve Research and Development (R&D) expenditure, which currently stands at approximately 0.7% of GDP in India.
  • The Index categorizes states into three groups: Major States (17), North East and Hill States (10), and Union Territories and City-States (9) to ensure a fair comparison based on geographical and administrative similarities.

Question 17

After independence till now, how many time/s Financial Emergency has/have been declared in India? 

  1. AOption (a)

    Once

  2. BOption (b)

    Twice

  3. COption (c)

    Four times

  4. DOption (d)

    Never

View answer & explanation

Correct answer

Answer: (d)D.

Never

Why this answer is correct

The correct answer is Never.

Key Points

  • Article 360 of the Constitution of India empowers the President to proclaim a Financial Emergency if he is satisfied that a situation has arisen whereby the financial stability or credit of India or any part of its territory is threatened.
  • To date, since the Constitution came into force on January 26, 1950, a Financial Emergency has never been declared in India. This remains true even during periods of significant economic stress.
  • Even during the severe Balance of Payments crisis in 1991, when India faced a critical shortage of foreign exchange reserves, the government chose to implement structural economic reforms (LPG - Liberalization, Privatization, and Globalization) rather than invoking Article 360.
  • The proclamation of a Financial Emergency must be approved by both Houses of Parliament (the Lok Sabha and the Rajya Sabha) within two months from the date of its issue.
  • Once approved by Parliament, the Financial Emergency continues indefinitely until it is revoked by the President. A repeated parliamentary approval is not required for its continuation, which is a unique feature compared to National Emergency.

Additional Information

  • Part XVIII of the Constitution of India (Articles 352 to 360) details the Emergency Provisions, which allow the Central Government to acquire exceptional powers to meet abnormal situations.
  • National Emergency (Article 352): This can be declared on the grounds of war, external aggression, or armed rebellion. In India, it has been declared three times: in 1962 (Chinese aggression), 1971 (Indo-Pak war), and 1975 (internal disturbance).
  • State Emergency / President's Rule (Article 356): This is invoked when the constitutional machinery in a state fails. It has been used over 100 times across various states in India since Independence.
  • Approval Mechanism: While a National Emergency requires a special majority for approval, a Financial Emergency can be passed by a simple majority in both Houses of Parliament.
  • Role of the Judiciary: The 38th Amendment Act of 1975 originally made the President's satisfaction final and conclusive, but the 44th Constitutional Amendment Act of 1978 subsequently made it subject to judicial review, ensuring that the declaration is not malafide.

Important Points

  • Consequences of Financial Emergency: During its operation, the executive authority of the Union extends to giving directions to any State to observe specified canons of financial propriety.
  • Salary Reductions: The President can issue directions for the reduction of salaries and allowances of all or any class of persons serving the Union or the States, including the Judges of the Supreme Court and the High Courts.
  • Money Bills: The Union can require that all Money Bills or other financial bills passed by the State Legislature be reserved for the consideration of the President.
  • Federal Structure: During a Financial Emergency, the Union gains full control over the financial matters of the States, significantly altering the federal balance of the Indian polity in favor of the Central Government.
  • Revocation: The President can revoke the proclamation at any time by a subsequent proclamation, which does not require parliamentary approval.

Question 18

A table that shows the scores and their frequency of occurrence is called 

  1. AOption (a)

    Data table

  2. BOption (b)

    Scores table

  3. COption (c)

    Frequency distribution table 

  4. DOption (d)

     Statistical table

View answer & explanation

Correct answer

Answer: (c)C.

Frequency distribution table 

Why this answer is correct

The correct answer is Frequency distribution table.

Key Points

  • A Frequency distribution table is a statistical tool used to organize and summarize data by showing the number of occurrences (frequency) of each distinct score or value in a dataset.
  • The primary function of this table is to transform raw data into a more meaningful and readable format, allowing researchers to see patterns and the spread of observations quickly.
  • It typically consists of two main columns: the first column lists the categories or score intervals, and the second column lists the frequency (f), which is the numerical value representing how many times that specific score appeared.
  • This table is fundamental in descriptive statistics as it provides the basis for creating graphs such as histograms, bar charts, and pie charts.
  • Regarding the other options: A Data table is a general term for any grid containing data; a Scores table is not a standard statistical term; and a Statistical table is a broad category that includes many types of tables, making Frequency distribution table the most specific and correct answer. Hence, the statement identifying the Frequency distribution table is correct.

Additional Information

  • Ungrouped Frequency Distribution: This type is used when the range of data is small. Each individual score is listed separately with its corresponding frequency. For example, if a teacher records test scores out of 10 for a small class, each number from 1 to 10 would be a row.
  • Grouped Frequency Distribution: This is used for large datasets where individual scores are grouped into class intervals (e.g., age groups like 20-29, 30-39). This helps in simplifying data that covers a wide numerical value range.
  • Relative Frequency: This feature shows the proportion or percentage of the total number of observations that fall into each category. It is calculated by dividing the frequency of a class by the total number of observations.
  • Cumulative Frequency: This is the sum of the frequencies for a specific class and all previous classes. It is particularly useful for identifying the median and percentiles within a data set.
  • Applications: These tables are used globally in census reports, market research, scientific experiments, and quality control in manufacturing to analyze the distribution of variables.

Important Points

  • Tally Marks: During the construction of the table, tally marks are often used as a manual counting method to ensure accuracy before the final numerical value of the frequency is recorded.
  • Class Limits and Midpoints: In grouped frequency distributions, the lower class limit and upper class limit define the boundaries of each group. The class midpoint (or class mark) is the average of the upper and lower limits and is used in various mathematical operations.
  • Measures of Central Tendency: The Frequency distribution table is the starting point for calculating the Mean, Median, and Mode for discrete or continuous data.
  • Range: The range is the difference between the highest and lowest numerical values in the data set, which helps in determining how many classes or intervals are needed in the table.
  • Rule of Thumb: In statistics, it is generally recommended to have between 5 to 15 class intervals to ensure the table is neither too detailed nor too vague.

Question 19

Consider the following figures and select the correct answer of the missing number from the code given below:

510
6075

 

36
36?
  1. AOption (a)

    ​40

  2. BOption (b)

    45

  3. COption (c)

    48

  4. DOption (d)

    60

View answer & explanation

Correct answer

Answer: (b)B.

45

Why this answer is correct

Logic Followed:

5 × 2 = 10 ⇒ 10 × 6 = 60 ⇒ 60 × 1.25 = 75

Similarly,

3 × 2 = 6 ⇒ 6 × 6 = 36 ⇒ 36 × 1.25 = 45

Thus, the correct answer is '45'.

Question 20

The average weight of 5 men increases by 2 kg, while one of the men whose weight is 60 kg, is replaced by a new man. What is the weight of new man? 

  1. AOption (a)

    50 kg

  2. BOption (b)

    65 kg

  3. COption (c)

    68 kg

  4. DOption (d)

    70 kg

View answer & explanation

Correct answer

Answer: (d)D.

70 kg

Why this answer is correct

Shortcut Trick

Weight of new man = Weight of replaced man + (Total number of men × Average increase)

Weight of new man = 60 + (5 × 2)

Weight of new man = 60 + 10 = 70 kg

∴ The correct answer is 70 kg.

Alternate Method

Given:

Number of men (n) = 5

Weight of the man replaced = 60 kg

Increase in average weight = 2 kg

Formula Used:

Total Increase = Number of items × Increase in average

New value = Old value + Total Increase

Old Man (60 kg)

+10 kg

New Man = 60 + (5 × 2) kg Weight Replacement Scale Result: 70 kg

⇒ Total weight increase = 5 × 2

⇒ Total weight increase = 10 kg

⇒ Weight of new man = 60 + 10

⇒ Weight of new man = 70 kg

∴ The correct answer is 70 kg.

Additional Information

Average Change on Replacement

When a person is replaced, New Weight = Replaced Weight + (Total Count × Change in Average). Use − for a decrease and + for an increase.

Average Change on Adding a Member

New Sum = (Old Average × Old Count) + New Member Weight. New Average = New Sum ÷ (Old Count + 1).

Weighted Average Formula

The combined average of two groups is given by (n1a1 + n2a2) ÷ (n1 + n2).

Question 21

In Ancient times, which of the Brahman families defeated all the contemporary rulers and established their own supremacy?

  1. AOption (a)

    Angiras

  2. BOption (b)

    Atri

  3. COption (c)

    Bhrigu

  4. DOption (d)

    Pulastya

View answer & explanation

Correct answer

Answer: (c)C.

Bhrigu

Why this answer is correct

The correct answer is Bhrigu.

Key Points

  • The Bhrigu family, also known as the Bhargavas, is a prominent Brahman lineage in ancient Indian history and mythology. They were renowned for their unique identity as both profound sages and exceptionally skilled warriors. Hence, this family is the correct answer.
  • The most celebrated member of the Bhrigu clan is Parasurama, who is revered as the sixth avatar of Lord Vishnu. According to the Puranas, he engaged in a legendary conflict with the Kshatriya (warrior) class to avenge the death of his father, Jamadagni.
  • Parasurama is traditionally said to have defeated all contemporary Kshatriya rulers and established his supremacy by cleansing the earth of the warrior class 21 times. This narrative highlights the era where the Bhrigu family asserted Brahmanical dominance over the temporal political powers of that age.
  • The family is also associated with the location of the western coast of India. It is believed that Parasurama reclaimed the land of Konkan and Kerala from the sea, where many Bhargava traditions continue to thrive.
  • The Bhrigu sages were also the authors of the Bhrigu Samhita, an astrological treatise, showcasing their influence over both scientific knowledge and military might in ancient times.

Additional Information

  • Angiras: This Brahman family is named after the sage Angiras, who is one of the Saptarishis (Seven Sages). They are the primary contributors to the Rigveda and the Atharvaveda. While spiritually powerful, the Angiras clan focused on rituals and hymns rather than the military conquest of rulers.
  • Atri: The Atri family descends from the sage Atri, another member of the Saptarishi. They are credited with the composition of the fifth Mandala of the Rigveda. They were highly respected as priests and advisors to various kings during the Vedic period but did not seek military supremacy.
  • Pulastya: The Pulastya lineage is distinct in mythology as it is the progenitor of the Rakshasa race through his son Vishrava. The Lanka king Ravana was a grandson of Pulastya. Although they possessed great power and knowledge, they are categorized differently from the Brahman families that upheld the Vedic social order.
  • Kshatriya-Brahman Conflict: In ancient India, particularly during the Later Vedic Period and the Epic Age, there were periodic shifts in the power dynamics of the Varna system. The story of the Bhargavas represents the most extreme historical/mythological example of Brahmanical intervention in governance.

Important Points

  • Kartavirya Arjuna: He was a powerful Haihaya king with 1000 arms who had initially received boons from Dattatreya. His conflict with the Bhrigu family began when he forcibly took the Kamadhenu (wish-granting cow) from Jamadagni’s hermitage, leading to the eventual war.
  • Role in Epics: Scholars often note the "Bhargavaization" of the Mahabharata, suggesting that the Bhrigu family played a significant role in compiling and expanding the epic over several centuries to include their family history and values.
  • Geographical Influence: The name of the city Bharuch in Gujarat is derived from Bhrigukachchha, indicating the deep-rooted location-based features of the Bhrigu family’s influence in Western India.
  • Date and Timeline: While these events are recorded in the Puranas, they are historically placed in the transition between the Early and Later Vedic societies, reflecting internal social and political evolutions in ancient India.

Question 22

Who was the author of the book entitled 'The Problems of the East'? 

  1. AOption (a)

    Jennifer Lawrence

  2. BOption (b)

    Lord Lytton 

  3. COption (c)

    George Curzon 

  4. DOption (d)

    Winston Churchill

View answer & explanation

Correct answer

Answer: (c)C.

George Curzon 

Why this answer is correct

The correct answer is George Curzon.

Key Points

  • George Curzon, also known as Lord Curzon, was the author of the prominent book titled 'Problems of the Far East' (often referred in historical contexts as 'The Problems of the East'), which was published in 1894.
  • The book provides a detailed analysis of the political, social, and economic conditions of Japan, Korea, and China during the late 19th century. It reflects his deep interest in geopolitics and the strategic importance of the Asian continent to the British Empire.
  • Curzon served as the Viceroy of India from 1899 to 1905. He was one of the most controversial yet efficient administrators during the British Raj. His tenure is marked by a series of reforms and administrative changes that significantly impacted the Indian subcontinent.
  • His writings and policies were heavily influenced by his belief in Imperialism and the necessity of maintaining British supremacy in the East. Apart from this book, he also authored 'Russia in Central Asia' (1889) and 'Persia and the Persian Question' (1892).
  • The mention of George Curzon as the author is a factual historical detail frequently asked in General Knowledge and History examinations. Hence, the statement regarding George Curzon being the author is correct.

Additional Information

  • Lord Curzon's Administration in India:
  • He was responsible for the Partition of Bengal in 1905, which was a major turning point in the Indian National Movement and led to the Swadeshi Movement.
  • He introduced the Ancient Monuments Preservation Act in 1904, which played a vital role in the restoration and protection of Indian heritage sites like the Taj Mahal.
  • He established the Agriculture Research Institute at Pusa (Bihar) in 1905 to modernize farming techniques in India.
  • He passed the Indian Universities Act in 1904 to bring higher education under stricter government control.
  • Lord Lytton (1876-1880):
  • He was the Viceroy of India during the Great Famine of 1876-1878.
  • He is known for passing the repressive Vernacular Press Act in 1878, which aimed at curbing the freedom of the Indian press.
  • He organized the Delhi Durbar in 1877, where Queen Victoria was proclaimed as the 'Kaiser-i-Hind'.
  • Winston Churchill:
  • He was the Prime Minister of the United Kingdom during World War II and a renowned statesman.
  • He was a prolific historian and writer, receiving the Nobel Prize in Literature in 1953.
  • His notable works include 'The Second World War' and 'A History of the English-Speaking Peoples'.
  • Jennifer Lawrence:
  • She is a famous American actress, born in 1990. She has no historical association with 19th-century political literature or British India.
  • She is widely known for her roles in films like 'The Hunger Games' and 'Silver Linings Playbook'.

Important Points

  • The book 'Problems of the Far East' was dedicated by Curzon to "those who believe that the British Empire is, under Providence, the greatest instrument for good that the world has seen."
  • During his Viceroyalty, Curzon also appointed the Raleigh Commission in 1902 to report on the prospects of universities in India.
  • He followed the 'Forward Policy' regarding the North-West Frontier and was instrumental in the Younghusband Expedition to Tibet in 1903-1904.
  • His administrative efficiency was often overshadowed by his autocratic style and his failure to recognize the growing nationalist sentiments among the Indian people.

Question 23

In which of the following states, 'Bagh Caves' are located? 

  1. AOption (a)

    Madhya Pradesh

  2. BOption (b)

    Bihar

  3. COption (c)

    Uttar Pradesh

  4. DOption (d)

    Rajasthan

View answer & explanation

Correct answer

Answer: (a)A.

Madhya Pradesh

Why this answer is correct

The correct answer is Madhya Pradesh.

Key Points

  • The Bagh Caves are a group of nine rock-cut monuments situated among the southern slopes of the Vindhya Range in the Dhar district of Madhya Pradesh. Hence, option 1 is correct.
  • These caves are famous for their mural paintings and are considered masterpieces of Buddhist art in India.
  • The caves were established during the 5th to 7th Century AD, which corresponds primarily to the late Gupta period.
  • Geographically, they are located on the banks of the Baghani River, which is a small tributary of the Narmada River.
  • Similar to the Ajanta Caves, these structures were not natural but were carved out of perpendicular sandstone rock surfaces.
  • While Bihar is known for ancient sites like Nalanda and the Barabar Caves, it is not the location of the Bagh Caves. Hence, option 2 is incorrect.
  • Uttar Pradesh is home to major Buddhist sites like Sarnath and Kushinagar, but the Bagh Caves are not situated here. Hence, option 3 is incorrect.
  • Rajasthan contains rock-cut structures like the Kolvi Caves, but the specific Bagh Caves are located in the central state of Madhya Pradesh. Hence, option 4 is incorrect.

Additional Information

  • Architectural Features: The Bagh Caves are primarily Viharas (monasteries), which served as residential quarters for Buddhist monks. Each cave usually contains a small Chaitya (prayer hall) at the rear, housing a Stupa.
  • The Paintings (Frescoes): The paintings at Bagh are executed in the Tempera technique. Unlike the purely religious themes at Ajanta, the Bagh mural paintings are more secular in nature, depicting music, dance, and social life of the Gupta era.
  • Cave 4 (Rang Mahal): This is the most significant cave among the group, famously known as the Palace of Colors. It contains the best-preserved and most elaborate murals depicting vibrant scenes of processions and dancers.
  • Discovery: These caves were "rediscovered" in 1818 by a British officer named Lieutenant Dangerfield. Before this, they were known to the local population but were hidden by dense vegetation.
  • Preservation Status: Due to the soft nature of the sandstone and the moisture from the Baghani River, many of the caves and paintings have deteriorated. The Archaeological Survey of India (ASI) has moved many original paintings to the Gwalior Fort Museum for protection.

Important Points

  • Historical Context: The Gupta Dynasty, under which these caves flourished, is often referred to as the Golden Age of India. This period saw a massive expansion in literature, science, and rock-cut architecture.
  • Comparison with Ajanta: While both are Buddhist and feature mural paintings, the Bagh Caves are considered more advanced in their secular depiction of human life compared to the Jataka tales focused paintings of Ajanta.
  • Numbering: Out of the 9 caves originally excavated, only 5 caves (Caves 1 through 5) are currently accessible and in a recognizable state. The others have collapsed over the centuries.
  • Religious Affiliation: These caves belong to the Mahayana sect of Buddhism, which is evidenced by the presence of Buddha statues and elaborate iconography.

Question 24

What is the name of the 'First Banking Robot' of India? C

  1. AOption (a)

    Lakshmi

  2. BOption (b)

    Pooja

  3. COption (c)

    Varun

  4. DOption (d)

    Param

View answer & explanation

Correct answer

Answer: (a)A.

Lakshmi

Why this answer is correct

The correct answer is Lakshmi.

Key Points

  • The first banking robot of India is named Lakshmi. It was launched by City Union Bank (CUB) in November 2016. This initiative was part of the bank's efforts to integrate Artificial Intelligence (AI) into its customer service operations.
  • The robot was first deployed at the City Union Bank branch located in Kumbakonam, Tamil Nadu. Its primary role was to assist customers with basic banking inquiries in a more interactive and efficient manner.
  • Lakshmi is capable of handling over 125 different types of customer queries. These include providing information on account balances, fixed deposit interest rates, loan products, and transaction history.
  • Technologically, the robot is based on the humanoid platform developed by SoftBank Robotics (originally Aldebaran Robotics from France). The City Union Bank team customized the software and integrated their specific banking database to make it functional for Indian customers.
  • The robot is equipped with Natural Language Processing (NLP), allowing it to understand and respond to customers in English. It was designed to move around the bank lobby and interact with people through voice and a touchscreen mounted on its chest.

Additional Information

  • IRA (Intelligent Robotic Assistant):
  • Following the launch of Lakshmi, HDFC Bank introduced its own banking robot named IRA in January 2017.
  • It was first deployed at the Kamala Mills branch in Mumbai. IRA was developed in collaboration with Asimov Robotics, a start-up based in Kochi, Kerala.
  • Advancements in Banking AI:
  • Apart from physical robots, Indian banks have heavily invested in Chatbots. For example, State Bank of India (SBI) launched SIA (SBI Intelligent Assistant) to handle customer queries via their website and app.
  • ICICI Bank introduced iPal, an AI-powered virtual assistant, to provide 24/7 support to its users.
  • The Global Context:
  • The use of robots in banking is inspired by global trends, such as the use of Pepper (the humanoid robot) by Mitsubishi UFJ Financial Group in Japan and HSBC in the United States.

Important Points

  • Security and Privacy:
  • While Lakshmi can provide general banking information, it is programmed not to store sensitive personal data like passwords or PIN numbers to ensure customer security and privacy.
  • For sensitive transactions, the robot directs the customer to a human bank official or a secure ATM/Kiosk.
  • Design and Mobility:
  • The robot stands about 3 to 4 feet tall and can perform gestures like waving or shaking hands to make the interaction feel more human-like.
  • It uses sensors to navigate the floor, ensuring it does not collide with customers or furniture within the bank premises.
  • Param:
  • It is important to note that Param (mentioned in the options) refers to a series of supercomputers designed and assembled by the Centre for Development of Advanced Computing (C-DAC) in India, with Param 8000 being the first, launched in 1991.

Question 25

Which one of the following is India's first commercial under-water Robotic Drone? 

  1. AOption (a)

    Focal

  2. BOption (b)

    Dornear-228

  3. COption (c)

    Eye Rov TUNA 

  4. DOption (d)

    Rustam

View answer & explanation

Correct answer

Answer: (c)C.

Eye Rov TUNA 

Why this answer is correct

The correct answer is Eye Rov TUNA.

Key Points

  • Eye Rov TUNA is recognized as India's first commercial underwater robotic drone, categorized as a Remotely Operated Vehicle (ROV).
  • It was officially launched and handed over to the Naval Physical and Oceanographic Laboratory (NPOL), a laboratory of the Defence Research and Development Organisation (DRDO), in September 2018.
  • The drone was developed by EyeROV Technologies, a startup based in Kochi, Kerala, and was incubated at Maker Village, which is one of the largest electronic hardware incubators in India.
  • This underwater drone is designed to perform visual inspections and surveys of submerged structures in environments where it is difficult or dangerous for human divers to operate.
  • The Eye Rov TUNA is a significant milestone in India's indigenous marine technology, providing a cost-effective alternative to expensive imported underwater inspection systems.

Additional Information

  • Features and Functions of Eye Rov TUNA:
  • Operating Depth: It is capable of diving up to depths of 50 to 100 meters in both freshwater and seawater environments.
  • Imaging: The drone is equipped with a High-Definition (HD) camera that provides real-time video feeds to the operator on the surface.
  • Control: It is controlled remotely via a tether (umbilical cable), which ensures steady communication and power supply during long durations of underwater operation.
  • Applications: Its primary applications include the inspection of ship hulls, underwater dam walls, bridge foundations, port structures, and submerged pipelines.
  • Other Options Explained:
  • Dornier-228: This is a multi-purpose light transport aircraft. In India, it is manufactured by Hindustan Aeronautics Limited (HAL) under license and is extensively used by the Indian Coast Guard and the Indian Navy for maritime surveillance and transport.
  • Rustom: This refers to the Rustom-1 or Rustom-2 (TAPAS-BH-201), which are Medium-Altitude Long-Endurance (MALE) Unmanned Aerial Vehicles (UAVs) developed by DRDO for aerial reconnaissance and surveillance.
  • Focal: This does not correspond to a major commercial underwater drone in the Indian defense or commercial context; it is often a general term related to optics or specific specialized sensors.

Important Points

  • Entrepreneurial Background: The startup EyeROV Technologies was founded by Johns T Mathai and Kannappa Palaniappan P, both alumni of IIT Delhi and IIT Madras.
  • Strategic Importance: The development of Eye Rov TUNA supports the Make in India initiative and the Deep Ocean Mission, aimed at exploring the vast marine resources of the Indian Ocean.
  • Data and Connectivity: The drone can be integrated with various sensors like Sonar for low-visibility conditions and ultrasonic thickness gauges to check the structural integrity of steel structures underwater.
  • Commercial Impact: By utilizing indigenous technology, the cost of underwater surveys has been reduced significantly, making it accessible for State Electricity Boards, Port Authorities, and Oil and Gas companies in India.

Question 26

In which of the following countries, the Indian Army launched rescue and relief work during natural disaster under 'Operation Samudra Maitri' in October, 2018? 

  1. AOption (a)

    Indonesia

  2. BOption (b)

    Bangladesh

  3. COption (c)

    Australia

  4. DOption (d)

    None of these

View answer & explanation

Correct answer

Answer: (a)A.

Indonesia

Why this answer is correct

The correct answer is Indonesia.

Key Points

  • Operation Samudra Maitri was a massive humanitarian operation launched by the Government of India in October 2018 to assist the victims of the earthquake and tsunami in Central Sulawesi, Indonesia.
  • The disaster was triggered by a 7.5-magnitude earthquake on September 28, 2018, followed by a devastating tsunami that primarily affected the city of Palu and surrounding areas.
  • As part of the operation, India dispatched two Indian Air Force (IAF) aircraft, specifically the C-130J Super Hercules and the C-17 Globemaster III, carrying a medical team and relief supplies such as tents and medicines.
  • The Indian Navy also mobilized three ships—INS Tir, INS Sujata, and INS Shardul—to deliver essential relief materials like food, clothing, and water to the affected country.
  • A field hospital was established by the Indian Army medical personnel to provide emergency medical care to the survivors in the location of the disaster.

Additional Information

  • India-Indonesia Relations: The operation highlighted the Comprehensive Strategic Partnership between India and Indonesia. Prime Minister Narendra Modi personally communicated with President Joko Widodo to offer assistance immediately after the disaster.
  • HADR Capabilities: This mission demonstrated India’s growing role as a Net Security Provider and a first responder in Humanitarian Assistance and Disaster Relief (HADR) operations within the Indian Ocean Region and the Indo-Pacific.
  • Magnitude of Disaster: The 2018 Sulawesi earthquake caused widespread soil liquefaction, which buried entire neighborhoods, leading to a high death toll exceeding 2,000 people and displacing thousands more.
  • Geographical Context: Indonesia is located on the Pacific Ring of Fire, making it highly susceptible to tectonic activities, volcanic eruptions, and natural disasters.
  • Relief Logistics: The IAF C-17 aircraft carried approximately 37 tonnes of medical equipment and supplies, while the C-130J carried a 60-member medical team including doctors and paramedics.

Important Points

  • The term "Samudra Maitri" translates to "Ocean Friendship", signifying the deep maritime and cultural ties between the two nations.
  • India’s "Act East Policy" and "SAGAR" (Security and Growth for All in the Region) initiative provide the strategic framework for such international cooperation and relief efforts.
  • Apart from Indonesia, India has historically launched similar operations, such as Operation Sahayata (for Mozambique in 2019) and Operation Vanilla (for Madagascar in 2020).
  • The Indian Navy ships involved in the operation were already deployed in the region for overseas training, allowing for a rapid response time to the emergency.

Question 27

Which of the following pairs is not matched about the Prayagraj Kumbh 2019? - 

  1. AOption (a)

    Makar Sankranti - 14 / (15 ^ (th)) Jan.

  2. BOption (b)

    Mauni Amavasya - 4th Feb.

  3. COption (c)

    Basant Panchami - 10th Feb.

  4. DOption (d)

    Maghi Poornima - 15th Feb.

View answer & explanation

Correct answer

Answer: (a)A.

Makar Sankranti - 14 / (15 ^ (th)) Jan.

Why this answer is correct

The correct answer is Maghi Poornima - 15th Feb..

Key Points

  • The Prayagraj Kumbh Mela held in 2019 was an Ardh Kumbh event, which occurs every 6 years. The event took place at the Triveni Sangam in Prayagraj, Uttar Pradesh.
  • Makar Sankranti - 14 / 15th Jan.: This marks the first official bathing day (Shahi Snan) of the Kumbh Mela. In 2019, the primary date for this auspicious festival was January 15, 2019. Hence, this statement is correctly matched.
  • Mauni Amavasya - 4th Feb.: Considered the most important and auspicious day for taking a holy dip in the Ganges, Mauni Amavasya in 2019 fell on February 4. It witnessed the largest gathering of pilgrims during the entire mela. Hence, this statement is correctly matched.
  • Basant Panchami - 10th Feb.: This day marks the arrival of Spring and is the third Shahi Snan. In 2019, it was celebrated on February 10. Hence, this statement is correctly matched.
  • Maghi Poornima - 15th Feb.: This is the full moon day of the Hindu month of Magh. In the year 2019, Maghi Poornima actually occurred on February 19, 2019, and not on February 15. Hence, this statement is not matched and is the correct answer.

Additional Information

  • Kumbh Mela Significance: It is one of the largest peaceful religious gatherings in the world. It was inscribed on the UNESCO Representative List of Intangible Cultural Heritage of Humanity in 2017.
  • Location and Cycle: The Kumbh Mela is held at four locations in India: Prayagraj (at the confluence of Ganges, Yamuna, and Saraswati), Haridwar (Ganges), Nashik (Godavari), and Ujjain (Shipra). A Purna Kumbh occurs every 12 years at each location.
  • 2019 Event Duration: The Prayagraj Ardh Kumbh lasted from January 15, 2019, to March 4, 2019. The Government of Uttar Pradesh and the Ministry of Culture played a significant role in its organization.
  • Guinness World Records: The 2019 event earned three Guinness World Records for the largest sanitation drive involving over 10,000 workers, the largest hand-painting exercise, and the largest parade of buses (over 500 buses).
  • Infrastructure and Scale: The temporary city set up for the mela covered an area of approximately 3,200 hectares and was divided into 20 sectors to manage the millions of devotees.

Important Points

  • Paushe Purnima: This was the official start of the mela on January 21, 2019, which signifies the beginning of the Kalpvas (a period of meditation and austerity).
  • Maha Shivratri: The final bathing day of the 2019 Kumbh was Maha Shivratri, which fell on March 4, 2019. This day marked the conclusion of the 48-day festival.
  • Key Organization: The Prayagraj Mela Authority was the primary organization responsible for the administrative setup, ensuring safety, and providing facilities like 1,22,000 toilets and 20,000 dustbins.
  • Digital Initiatives: For the first time, the Digital Kumbh initiative was launched, including a mobile app to help pilgrims navigate the location and locate lost persons.

Question 28

In January 2019, Sheikh Hasina Wazed of Awami League became Prime Minister of Bangladesh for which term? 

  1. AOption (a)

    1sttime

  2. BOption (b)

    3rd time

  3. COption (c)

    4thtime

  4. DOption (d)

    5th time

View answer & explanation

Correct answer

Answer: (c)C.

4thtime

Why this answer is correct

The correct answer is 4th time.

Key Points

  • Sheikh Hasina Wazed, the leader of the Awami League, was sworn in as the Prime Minister of Bangladesh for the 4th time (and third consecutive term) on 7 January 2019. This followed her party's landslide victory in the 11th Parliamentary Election held on 30 December 2018. Hence, statement 3 is correct.
  • She previously served as the Prime Minister during the following periods: her first term was from 1996 to 2001; her second term began in 2009 and lasted until 2014; and her third term spanned from 2014 to 2019. Hence, statements 1 and 2 are incorrect in the context of the January 2019 appointment.
  • The January 2019 inauguration solidified her position as the longest-serving Prime Minister in the history of Bangladesh. Under her leadership, the Grand Alliance led by the Awami League won an overwhelming 288 seats out of the 300 directly elected seats in the Jatiya Sangsad (Parliament).
  • During the swearing-in ceremony held at the Bangabhaban in Dhaka, President Abdul Hamid administered the oath of office to Sheikh Hasina and her new cabinet members.
  • The 5th term for Sheikh Hasina only commenced much later, following the general elections held in January 2024. Therefore, in January 2019, she was entering her 4th term. Hence, statement 4 is incorrect.

Additional Information

  • Political Career of Sheikh Hasina:
  • She is the daughter of Sheikh Mujibur Rahman, the founding father and the first President of Bangladesh, often referred to as Bangabandhu.
  • Sheikh Hasina has been the President of the Bangladesh Awami League since 1981. She returned to Bangladesh from exile in India in May 1981 to lead the pro-democracy movement against military rule.
  • Her leadership is noted for significant economic growth, with Bangladesh maintaining a high GDP growth rate and transitioning from a "Least Developed Country" to a "Developing Country" status as per United Nations criteria.
  • Bangladesh Government Structure:
  • Bangladesh follows a Parliamentary Form of Government where the Prime Minister is the Head of Government, and the President is the Head of State.
  • The Jatiya Sangsad is the unicameral legislature, consisting of 350 members, where 300 members are directly elected and 50 seats are reserved for women.
  • The Constitution of Bangladesh was adopted on 4 November 1972, establishing a secular and democratic republic.
  • Key Achievements and Facts:
  • Under her tenure, the Ganges Water Sharing Treaty with India was signed in 1996, and the Chittagong Hill Tracts Peace Accord was signed in 1997.
  • In 2015, the Land Boundary Agreement (LBA) was implemented between India and Bangladesh, resolving decades-old enclave disputes through the 100th Constitutional Amendment Act of India.
  • She has received numerous international awards, including the UNESCO Houphouët-Boigny Peace Prize and the UN "Champions of the Earth" award in 2015 for her leadership in addressing climate change.
  • Geopolitical Context:
  • Bangladesh is a founding member of SAARC (South Asian Association for Regional Cooperation) and an active member of BIMSTEC (Bay of Bengal Initiative for Multi-Sectoral Technical and Economic Cooperation).
  • The capital city is Dhaka, and the national currency is the Bangladeshi Taka (BDT). As of 2019, the country had made significant strides in human development indices, particularly in maternal health and female education.

Question 29

Prime Minister Narendra Modi released a new coin in the memory of Former Prime Minister Late Shri Atal Bihari Vajpayee in Dec. 2018. It is a ____ . 

  1. AOption (a)

    200 Rupee Coin

  2. BOption (b)

    100 Rupee Coin

  3. COption (c)

    50 Rupee Coin

  4. DOption (d)

    500 Rupee Coin

View answer & explanation

Correct answer

Answer: (b)B.

100 Rupee Coin

Why this answer is correct

The correct answer is 100 Rupee Coin.

Key Points

  • Prime Minister Narendra Modi released a commemorative 100 Rupee Coin in memory of former Prime Minister Atal Bihari Vajpayee on December 24, 2018.
  • The coin was released just a day before the 94th birth anniversary of the late leader, who passed away in August 2018.
  • The 100 Rupee Coin weighs 35 grams and has a diameter of 44 millimeters.
  • The metal composition of the coin is a quaternary alloy consisting of 50% Silver, 40% Copper, 5% Nickel, and 5% Zinc.
  • On the reverse side of the coin, there is a portrait of Atal Bihari Vajpayee with the inscription "Atal Bihari Vajpayee" written in Devanagari script and English. The years 1924 and 2018 are also inscribed below the portrait to signify his birth and death years.
  • The obverse side of the coin features the Lion Capital of Ashoka Pillar in the center with the legend "Satyamev Jayate" inscribed below it. The word "Bharat" in Hindi and "India" in English are flanked on the left and right sides respectively.

Additional Information

  • Atal Bihari Vajpayee:
  • He served as the 10th Prime Minister of India for three terms: first for 13 days in 1996, then for 13 months in 1998-1999, and finally for a full term from 1999 to 2004.
  • He was a co-founder of the Bharatiya Janata Party (BJP) and was the first non-Congress Prime Minister to serve a full five-year term.
  • In 2015, he was conferred with India's highest civilian honor, the Bharat Ratna, by the President of India.
  • His birthday, December 25, is celebrated annually as Good Governance Day (Sushasan Divas) in India to honor his legacy of transparent and accountable administration.
  • Commemorative Coins in India:
  • These coins are issued by the Government of India to honor distinguished personalities, monumental events, or historical milestones.
  • Unlike regular circulation coins, commemorative coins of high denominations (like 100, 125, or 150 rupees) are usually not intended for general trade but are available as collectors' items through the India Government Mint.
  • The Ministry of Finance has the sole authority to design and decide the denominations of these coins under the Coinage Act, 2011.

Important Points

  • Significance of the Release: The release of the 100 Rupee Coin was a tribute to Vajpayee's contribution to Indian politics and his role as a "Man of the Masses."
  • Location of Release: The event took place in New Delhi in the presence of several dignitaries, including Amit Shah and L.K. Advani.
  • Other Commemorative Denominations: While the question focuses on the 100 Rupee Coin for Vajpayee, the Indian government has also released other denominations like 75 Rupee Coin (for the 75th anniversary of FAO) and 125 Rupee Coin (for the birth anniversary of Paramahansa Yogananda) in different years.
  • Design Standards: The circular shape and the serrated edge are standard for such high-value commemorative issues produced by the Mumbai or Kolkata Mints.

Question 30

Shaheed Nazir Ahmad of Jammu and Kashmir sacrificed his life fighting against terrorists in Nov. 2018. He was posthumously awarded _____ . 

  1. AOption (a)

    Ashoka Chakra

  2. BOption (b)

    Mahavir Chakra 

  3. COption (c)

    Saurya Chakra

  4. DOption (d)

    Kirti Chakra

View answer & explanation

Correct answer

Answer: (a)A.

Ashoka Chakra

Why this answer is correct

The correct answer is Ashoka Chakra.

Key Points

  • Lance Naik Nazir Ahmad Wani, a soldier from the Jammu and Kashmir region, was posthumously awarded the Ashoka Chakra in January 2019.
  • He sacrificed his life during a fierce counter-terrorist operation in Shopian district, Jammu and Kashmir, on November 25, 2018.
  • During the operation at Hirapur village, despite being severely wounded, he displayed exemplary courage by eliminating a district commander of the Hizbul Mujahideen and another foreign terrorist in close-quarter combat.
  • He belonged to the 162 Infantry Battalion Territorial Army (Home and Hearth) and was operating with the 34 Rashtriya Rifles at the time of his martyrdom.
  • The Ashoka Chakra is India's highest peacetime military decoration, awarded for most conspicuous bravery or self-sacrifice away from the battlefield. Hence, the option Ashoka Chakra is correct.

Additional Information

  • Kirti Chakra:
  • It is the second-highest peacetime gallantry award in India.
  • It is awarded for conspicuous gallantry otherwise than in the face of the enemy.
  • It was originally established as the Ashoka Chakra, Class II in 1952 and renamed in 1967.
  • Shaurya Chakra:
  • It is the third-highest peacetime gallantry award.
  • It is generally awarded for counter-insurgency operations and actions against the enemy during peacetime.
  • It was originally known as the Ashoka Chakra, Class III.
  • Mahavir Chakra:
  • It is the second-highest wartime gallantry award in India.
  • It is awarded for acts of conspicuous gallantry in the presence of the enemy, whether on land, at sea, or in the air.
  • It is distinct from peacetime awards as it specifically requires a state of war or active conflict with an external enemy.
  • Ashoka Chakra Selection:
  • The award can be conferred upon military personnel as well as civilians.
  • It is the peacetime equivalent of the Param Vir Chakra.

Important Points

  • Lance Naik Nazir Ahmad Wani hailed from Cheki Ashmuji in Kulgam district of Jammu and Kashmir.
  • His life story is remarkable as he was once a militant (an Ikhwan) who realized the futility of violence and joined the Indian Army in 2004.
  • Prior to the Ashoka Chakra, he was a highly decorated soldier having received the Sena Medal for gallantry twice (in 2007 and 2018).
  • The award was presented by President Ram Nath Kovind to his wife, Mahajabeen, during the 70th Republic Day parade in 2019.
  • The Ministry of Defence is the nodal agency that processes these gallantry awards, which are announced twice a year—on Republic Day and Independence Day.

Part II (120 questions)

Question 31

The site for dark reaction during photosynthesis is

  1. AOption (a)

    Grana

  2. BOption (b)

    Stroma

  3. COption (c)

    Mitochondria

  4. DOption (d)

    Both (a) and (b)

View answer & explanation

Correct answer

Answer: (b)B.

Stroma

Why this answer is correct

The correct answer is - Stroma

Key Points

  • Stroma
  • The dark reaction (also known as the Calvin cycle or light-independent reaction) occurs in the stroma of the chloroplast.
  • This process does not require direct light but relies on the products of the light reaction, specifically ATP and NADPH.
  • During this phase, carbon dioxide is fixed and reduced to form glucose (sugar) through a series of enzymatic steps.

Additional Information

  • Photosynthesis
  • It is the process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll.
  • It consists of two main stages:
  • Light Reaction: Occurs in the grana (thylakoids). It involves the trapping of solar energy and the splitting of water to produce oxygen, ATP, and NADPH.
  • Dark Reaction: Occurs in the stroma. It involves the reduction of CO2 into carbohydrates using ATP and NADPH.
  • Grana
  • Grana are stacks of thylakoids embedded in the stroma of a chloroplast.
  • They are the site of the photochemical phase where light energy is converted into chemical energy.
  • Mitochondria
  • These are known as the powerhouse of the cell and are the primary site for cellular respiration (ATP production), not photosynthesis.

Question 32

Enzymes which take part in glycolysis are found in

  1. AOption (a)

    Mitochondria

  2. BOption (b)

    Cytoplasm

  3. COption (c)

    Endoplasmic Reticulum

  4. DOption (d)

     Both (a) and (b)

View answer & explanation

Correct answer

Answer: (b)B.

Cytoplasm

Why this answer is correct

The correct answer is - Cytoplasm

Key Points

  • Cytoplasm
  • The enzymes responsible for glycolysis are located in the cytoplasm (specifically the cytosol) of the cell.
  • Glycolysis is a universal pathway occurring in both prokaryotic and eukaryotic cells because it does not require membrane-bound organelles like mitochondria to proceed.
  • This pathway involves ten distinct enzymes, such as hexokinase, phosphofructokinase, and pyruvate kinase, all of which are soluble in the cytosolic fluid.

Additional Information

  • Glycolysis
  • It is the process of breaking down glucose (a 6-carbon compound) into two molecules of pyruvate (a 3-carbon compound).
  • It is an anaerobic process, meaning it can occur whether oxygen is present or not.
  • The net yield of glycolysis is 2 ATP and 2 NADH molecules per glucose molecule.
  • Mitochondria vs. Cytoplasm
  • While glycolysis occurs in the cytoplasm, the subsequent stages of aerobic respiration, such as the Krebs Cycle (TCA cycle) and the Electron Transport Chain, occur inside the mitochondria.
  • The pyruvate produced in the cytoplasm is transported into the mitochondria for further oxidation in the presence of oxygen.
  • Endoplasmic Reticulum
  • The Endoplasmic Reticulum is primarily involved in protein synthesis (Rough ER) and lipid synthesis or detoxification (Smooth ER), rather than the primary metabolic pathways of carbohydrate breakdown like glycolysis.

Question 33

Which of the following is involved in plant defense ?

  1. AOption (a)

    Kinetin

  2. BOption (b)

    Zeatin

  3. COption (c)

    Jasmonate

  4. DOption (d)

    A.T.P. Synthetase

View answer & explanation

Correct answer

Answer: (c)C.

Jasmonate

Why this answer is correct

The correct answer is - Jasmonate

Key Points

  • Jasmonate
  • Jasmonates (Jasmonic acid and its derivatives) are lipid-derived plant hormones that play a critical role in plant defense.
  • They are particularly vital for defense against herbivorous insects and necrotrophic pathogens (pathogens that kill host cells to feed).
  • When a plant is wounded or attacked, Jasmonates trigger the expression of defense genes that lead to the production of anti-digestive proteins (like protease inhibitors) and toxic secondary metabolites.

Additional Information

  • Cytokinins (Kinetin and Zeatin)
  • Kinetin (synthetic) and Zeatin (natural) are types of cytokinins.
  • Their primary function is to promote cell division (cytokinesis) and delay leaf senescence; they are not the primary signaling molecules for defense.
  • A.T.P. Synthetase
  • A.T.P. Synthetase is an enzyme complex found in mitochondria and chloroplasts.
  • It is responsible for the synthesis of ATP (energy) during cellular respiration and photosynthesis, rather than being a defense signaling hormone.
  • Defense Pathways
  • Plants use two main pathways for biotic defense: the Jasmonic Acid (JA) pathway for wounding/insects and the Salicylic Acid (SA) pathway for biotrophic pathogens (like viruses and certain fungi).
  • These pathways often show antagonistic cross-talk to help the plant prioritize the most effective defense mechanism.

Question 34

Nitrogen fixation in ulnus root nodules is due to

  1. AOption (a)

    Azotobacter

  2. BOption (b)

    Clostridium

  3. COption (c)

    Rhizobium

  4. DOption (d)

    Frankia

View answer & explanation

Correct answer

Answer: (d)D.

Frankia

Why this answer is correct

The correct answer is - Frankia

Key Points

  • Frankia
  • Frankia is a genus of nitrogen-fixing bacteria that lives in symbiotic association with actinorhizal plants, such as Alnus (Alder).
  • Unlike Rhizobium, which forms nodules on the roots of leguminous plants, Frankia forms nodules on non-leguminous plants.
  • These bacteria are filamentous and belong to the group known as Actinomycetes.
  • The symbiotic relationship allows the plant to grow in nitrogen-poor soils by converting atmospheric nitrogen into a form the plant can use.

Additional Information

  • Symbiotic Nitrogen Fixers
  • Rhizobium: Primarily associates with leguminous plants like peas, beans, and clover to form root nodules.
  • Frankia: Associates with non-leguminous plants like Alnus, Casuarina, and Myrica.
  • Free-living Nitrogen Fixers
  • Azotobacter: A free-living, aerobic nitrogen-fixing bacterium commonly found in neutral or alkaline soils.
  • Clostridium: An anaerobic bacterium that can fix nitrogen in the absence of oxygen.
  • Beijerinckia: Another free-living aerobic nitrogen fixer, often found in tropical soils.
  • Nitrogen Fixation Process
  • It involves the conversion of atmospheric Nitrogen (N2) into Ammonia (NH3).
  • This process is catalyzed by the enzyme nitrogenase, which is highly sensitive to molecular oxygen.

Question 35

Pseudoembryosac is found in

  1. AOption (a)

    Podostemoniaceae

  2. BOption (b)

    Convolvulaceae

  3. COption (c)

    Solanaceae

  4. DOption (d)

    Chenopodiaceae

View answer & explanation

Correct answer

Answer: (a)A.

Podostemoniaceae

Why this answer is correct

The correct answer is - Podostemoniaceae

Key Points

  • Pseudo-embryo sac
  • A pseudo-embryo sac is a unique embryological feature found specifically in the family Podostemoniaceae.
  • It is formed by the disintegration and dissolution of the nucellar cells situated immediately below the embryo sac.
  • The breakdown of these cells creates a large, longitudinal hollow cavity containing several free nuclei and dense cytoplasm, which is often referred to as a nucellar plasmodium.

Additional Information

  • Significance of Pseudo-embryo sac
  • In the family Podostemoniaceae, the process of triple fusion does not occur, which means that endosperm (the typical nutritive tissue) is not formed.
  • The pseudo-embryo sac functions as a replacement for the endosperm, providing the necessary nutrition to the developing proembryo.
  • Podostemoniaceae Characteristics
  • Plants of this family are aquatic herbs, usually found submerged in fast-flowing freshwater streams or waterfalls.
  • Their morphological and embryological characters are highly specialized due to their unique habitat.
  • Comparison with Other Families
  • Solanaceae, Convolvulaceae, and Chenopodiaceae generally show standard 8-nucleate (Polygonum type) embryo sac development and possess regular endosperm.

Question 36

Bisporic embryosac is found in

  1. AOption (a)

    Allium

  2. BOption (b)

    Oenothera

  3. COption (c)

    Fritillaria

  4. DOption (d)

    Polygonum

View answer & explanation

Correct answer

Answer: (a)A.

Allium

Why this answer is correct

The correct answer is - Allium

Key Points

  • Bisporic Embryo Sac (Allium type)
  • In Allium, the embryo sac is bisporic, meaning it develops from two megaspore nuclei.
  • During megasporogenesis, the first meiotic division is followed by wall formation, resulting in a dyad of cells.
  • In the second meiotic division, nuclear division occurs without cytokinesis. One of the dyad cells degenerates, and the remaining cell (containing two nuclei) undergoes further mitotic divisions to form an eight-nucleate embryo sac.
  • This type of development is characteristic of the genus Allium and Endymion.

Additional Information

  • Monosporic Embryo Sac
  • Polygonum: This is the most common type where the embryo sac develops from a single megaspore (usually the chalazal one). It is an 8-nucleate, 7-celled structure.
  • Oenothera: This is also monosporic but results in a 4-nucleate embryo sac because only two mitotic divisions occur after meiosis.
  • Tetrasporic Embryo Sac
  • Fritillaria: In this type, meiosis is not followed by cytokinesis, so all four megaspore nuclei participate in forming the embryo sac.
  • It involves complex nuclear fusions (Carano-Bambacioni effect) to produce a triploid and a haploid set of nuclei.
  • Comparison Summary
  • Monosporic: 1 megaspore nucleus (e.g., Polygonum, Oenothera).
  • Bisporic: 2 megaspore nuclei (e.g., Allium).
  • Tetrasporic: 4 megaspore nuclei (e.g., Fritillaria, Adoxa).

Question 37

Which plant part is used for extraction of opium from Papaver somniferum?

  1. AOption (a)

    Ripe capsule

  2. BOption (b)

    Unripe capsule

  3. COption (c)

    Mature leaves

  4. DOption (d)

    Mature seeds

View answer & explanation

Correct answer

Answer: (b)B.

Unripe capsule

Why this answer is correct

The correct answer is - Unripe capsule

Key Points

  • Extraction of Opium
  • Opium is a naturally occurring substance obtained from the plant Papaver somniferum, commonly known as the opium poppy.
  • The primary part used for extraction is the unripe capsule (the seed pod).
  • When the capsule is green and unripe, small incisions are made on the outer surface. A milky fluid called latex exudes from these cuts.
  • This latex is then collected and dried to form raw opium, which contains various alkaloids.

Additional Information

  • Alkaloids in Opium
  • Opium contains several medically important alkaloids such as morphine, codeine, and thebaine.
  • Morphine is a powerful analgesic (pain reliever) used in clinical settings to manage severe pain.
  • Plant Taxonomy
  • The opium poppy belongs to the family Papaveraceae.
  • It is primarily grown in dry, warm climates across parts of Asia and Southeast Europe.
  • Other Plant Parts
  • Poppy Seeds: These are the mature seeds found inside the ripe capsule. They are widely used in culinary applications and contain negligible amounts of alkaloids.
  • Ripe Capsule: Once the capsule reaches maturity and dries out, it no longer yields the latex used for opium production.

Question 38

Which ecological pyramid is always upright?

  1. AOption (a)

    Pyramid of biomass

  2. BOption (b)

    Pyramid of number

  3. COption (c)

    Pyramid of energy

  4. DOption (d)

    Both (b) and (c)

View answer & explanation

Correct answer

Answer: (c)C.

Pyramid of energy

Why this answer is correct

The correct answer is - Pyramid of energy

Key Points

  • Pyramid of Energy
  • The Pyramid of energy is always upright and can never be inverted.
  • This is because when energy flows from a particular trophic level to the next trophic level, some energy is always lost as heat at each step.
  • It represents the total amount of energy utilized by organisms at each trophic level per unit area and time.
  • The base of the energy pyramid is always occupied by producers, who possess the maximum energy.

Additional Information

  • Pyramid of Number
  • It represents the total number of individual organisms at different trophic levels in an ecosystem.
  • It can be upright (e.g., grassland ecosystem) or inverted (e.g., a single tree supporting many insects and birds).
  • Pyramid of Biomass
  • It represents the total living organic matter or standing crop at each trophic level.
  • In most terrestrial ecosystems, it is upright.
  • In aquatic ecosystems (like a pond or ocean), it is often inverted because the biomass of consumers (fish) exceeds the biomass of producers (phytoplankton).
  • 10 Percent Law
  • Introduced by Raymond Lindeman, it states that only 10% of the energy available at one trophic level is transferred to the next higher trophic level.
  • This gradual loss of energy limits the number of trophic levels in a food chain.

Question 39

Stylopodium is found in

  1. AOption (a)

    Papaveraceae

  2. BOption (b)

    Apiaceae

  3. COption (c)

    Acanthaceae

  4. DOption (d)

    Solanaceae

View answer & explanation

Correct answer

Answer: (b)B.

Apiaceae

Why this answer is correct

The correct answer is - Apiaceae

Key Points

  • Stylopodium
  • The stylopodium is a distinct fleshy, glandular disk or an enlargement found at the base of the styles on top of the ovary.
  • It is a characteristic morphological feature of the family Apiaceae (formerly known as Umbelliferae).
  • This structure typically functions as a nectary, secreting nectar to attract various insect pollinators.

Additional Information

  • Apiaceae Family Characteristics
  • Inflorescence: The most common inflorescence type is the umbel (simple or compound).
  • Gynoecium: It has a bicarpellary, syncarpous, and inferior ovary.
  • Fruit: The characteristic fruit is a cremocarp, which is a type of schizocarp that splits into two mericarps.
  • Examples include Coriander, Carrot, Fennel, and Cumin.
  • Other Mentioned Families
  • Papaveraceae: Commonly known as the poppy family; they usually have flowers with many stamens and a fruit that is a capsule.
  • Solanaceae: Known as the nightshade family; features include an oblique ovary and fruit being a berry or capsule (e.g., Potato, Tomato).
  • Acanthaceae: Known for having bracts and bracteoles, zygomorphic flowers, and fruit that is usually a loculicidal capsule.

Question 40

Wart disease of potato is caused by

  1. AOption (a)

    Phytophthora infestans

  2. BOption (b)

    Alternaria alternata

  3. COption (c)

    Synchytrium endobiotium

  4. DOption (d)

    Rhizoctonia solani

View answer & explanation

Correct answer

Answer: (c)C.

Synchytrium endobiotium

Why this answer is correct

The correct answer is - Synchytrium endobiotium

Key Points

  • Synchytrium endobiotium
  • Wart disease of potato is caused by the fungus Synchytrium endobiotium (also known as Synchytrium endobioticum).
  • It is a biotrophic, obligate parasite that belongs to the phylum Chytridiomycota.
  • The most prominent symptom is the development of wart-like outgrowths on the potato tubers, which resemble cauliflower heads.
  • The pathogen induces hyperplasia (excessive cell division) and hypertrophy (excessive cell enlargement) in the host tissues.

Additional Information

  • Disease Spread and Survival
  • The disease is soil-borne and the resting sporangia can survive in the soil for as long as 20–30 years.
  • It is a quarantine pest in many countries because it is extremely difficult to eradicate once established in the soil.
  • Comparison with Other Pathogens
  • Phytophthora infestans: This is an oomycete responsible for Late Blight of potato, which famously caused the Irish Potato Famine.
  • Alternaria alternata: While Alternaria solani causes Early Blight of potato, Alternaria alternata can cause various leaf spot diseases and is a common opportunistic pathogen.
  • Rhizoctonia solani: This soil-borne fungus causes Black Scurf and Stem Canker in potatoes, characterized by hard black sclerotia on the tuber surface.

Question 41

Cleistogemy is found in

  1. AOption (a)

    Commelina

  2. BOption (b)

    Catharanthus

  3. COption (c)

    Mirabilis

  4. DOption (d)

    Salvia

View answer & explanation

Correct answer

Answer: (a)A.

Commelina

Why this answer is correct

The correct answer is - Commelina

Key Points

  • Cleistogamy
  • Cleistogamy is a condition where flowers do not open at all, ensuring that self-pollination occurs within the closed bud.
  • In such flowers, the anthers and stigma lie close to each other. When anthers dehisce in the flower buds, pollen grains come in contact with the stigma for pollination.
  • Commelina (e.g., Commelina benghalensis) is a well-known example that produces two types of flowers: Chasmogamous (open flowers) and Cleistogamous (closed flowers).

Additional Information

  • Types of Flowers in Commelina
  • Chasmogamous flowers: These are similar to flowers of other species with exposed anthers and stigma. They facilitate cross-pollination.
  • Cleistogamous flowers: These are often found underground or near the soil surface and never open. They ensure an assured seed-set even in the absence of pollinators.
  • Examples of Cleistogamy
  • Plants like Viola (common pansy), Oxalis, and Commelina produce both chasmogamous and cleistogamous flowers.
  • Advantages and Disadvantages
  • Advantage: It guarantees seed production without relying on external pollination agencies like wind, water, or insects.
  • Disadvantage: Since there is no cross-pollination, it leads to inbreeding and lacks genetic variation.
  • Other Options
  • Catharanthus, Mirabilis (Four o clock plant), and Salvia generally bear chasmogamous flowers that open for cross-pollination.

Question 42

Pollination by bats takes place in

  1. AOption (a)

    Opuntia

  2. BOption (b)

    Kigelia

  3. COption (c)

    Azadirachta

  4. DOption (d)

    None of the above

View answer & explanation

Correct answer

Answer: (b)B.

Kigelia

Why this answer is correct

The correct answer is - Kigelia

Key Points

  • Kigelia
  • Kigelia, commonly known as the sausage tree, is pollinated by bats.
  • Bats play a key role as nocturnal pollinators, attracted to flowers with features such as:
  • Large size and accessible structure for bats to feed.
  • Strong nocturnal scent that attracts bats during nighttime.
  • Nectar-rich flowers that serve as a food source for bats.
  • This method of pollination is termed Chiropterophily, referring specifically to pollination by bats.
  • Kigelia is adapted to bat pollination with its hanging flowers that facilitate bat access.

Additional Information

  • Pollination by bats
  • Bats are important pollinators for several tropical and subtropical plants.
  • Plants pollinated by bats often exhibit:
  • Dusky or pale-colored flowers that are visible at night.
  • A strong fragrance that is emitted during nighttime to attract bats.
  • Flowers that hang or grow in locations accessible to bats.
  • Other examples of bat-pollinated plants
  • Ceiba pentandra (Kapok tree).
  • Adansonia (Baobab tree).
  • These plants share similar adaptations for bat pollination, such as nocturnal blooming and nectar-rich flowers.

Question 43

Iberis amara belongs to the family

  1. AOption (a)

    Oleaceae

  2. BOption (b)

    Brassicaceae

  3. COption (c)

    Polygonaceae

  4. DOption (d)

    Fabaceae

View answer & explanation

Correct answer

Answer: (b)B.

Brassicaceae

Why this answer is correct

The correct answer is - Brassicaceae

Key Points

  • Iberis amara
  • Iberis amara, commonly known as Rocket Candytuft or Bitter Candytuft, is an annual flowering plant used for ornamental and medicinal purposes.
  • It belongs to the family Brassicaceae, which was formerly known as Cruciferae.
  • The name Cruciferae refers to the four petals of the flower, which are arranged in the shape of a cross.

Additional Information

  • Brassicaceae Family
  • This family includes many economically important plants such as Mustard (Brassica nigra), Cabbage (Brassica oleracea), and Radish (Raphanus sativus).
  • Distinguishing features include tetradynamous stamens (four long and two short) and the presence of glucosinolates.
  • The fruit is typically a siliqua or silicula.
  • Other Families Mentioned
  • Oleaceae: This is the olive family, which includes plants like Olea europaea (olive), Fraxinus (ash), and Jasminum (jasmine).
  • Polygonaceae: Known as the buckwheat or knotweed family, characterized by ochreate stipules (a sheath around the stem at the node).
  • Fabaceae: Known as the legume or pea family, characterized by papilionaceous corolla and legume type fruit.

Question 44

Reniform anthers are present in

  1. AOption (a)

    Ranunculaceae

  2. BOption (b)

    Malvaceae

  3. COption (c)

    Lamiaceae

  4. DOption (d)

    Papaveraceae

View answer & explanation

Correct answer

Answer: (b)B.

Malvaceae

Why this answer is correct

The correct answer is - Malvaceae

Key Points

  • Reniform Anthers
  • The term reniform refers to a kidney-shaped appearance.
  • In the family Malvaceae, the anthers are typically monothecous (one-lobed) and reniform in shape.
  • This shape is a distinguishing morphological feature used to identify members of this family, such as Hibiscus and Cotton.

Additional Information

  • Malvaceae Family Characteristics
  • Monadelphous Stamens: The filaments of the stamens are fused together to form a staminal tube around the style.
  • The anthers are attached to the upper part of this tube and are extrorse (opening outwards).
  • Common examples include Hibiscus rosa-sinensis (China rose), Gossypium (Cotton), and Abelmoschus esculentus (Lady finger).
  • Comparison with Other Families
  • Ranunculaceae: Usually possesses numerous stamens that are dithecous (two-lobed) and spirally arranged.
  • Lamiaceae: Characterized by didynamous stamens (two long and two short) with dithecous anthers.
  • Papaveraceae: Features numerous stamens with dithecous anthers that are usually extrorse.
  • Anther Terminology
  • Monothecous: An anther with only one lobe or pollen sac (common in Malvaceae).
  • Dithecous: A typical anther consisting of two lobes (found in most angiosperm families).

Question 45

Muriform Conidia are found in

  1. AOption (a)

    Fusarium

  2. BOption (b)

    Alternaria

  3. COption (c)

    Colletotrichum

  4. DOption (d)

    Cercospora

View answer & explanation

Correct answer

Answer: (a)A.

Fusarium

Why this answer is correct

The correct answer is - Muriform conidia are found in Fusarium

Key Points

  • Muriform conidia
  • Muriform conidia are characterized by their multicellular appearance formed by both transverse and longitudinal septa.
  • They are also referred to as phragmoconidia in fungal taxonomy.
  • These structures are typically found in Fusarium, which are plant pathogenic fungi causing diseases such as Fusarium wilt.
  • Distinct features of Fusarium
  • Fusarium produces muriform conidia that serve as its reproductive structures and play a significant role in its pathogenicity.
  • It is commonly associated with soil-borne pathogens, which affect crops like wheat, maize, and bananas.

Additional Information

  • Alternaria
  • Alternaria produces dictyospores, which are multicellular conidia but lack the muriform arrangement.
  • These spores are usually involved in plant diseases such as leaf spots and blights.
  • Colletotrichum
  • Colletotrichum primarily produces unicellular conidia, which are cylindrical in shape.
  • This genus is known for causing anthracnose diseases in plants.
  • Cercospora
  • Cercospora produces filiform conidia, which are long and thread-like.
  • It is responsible for diseases such as Cercospora leaf spot.

Question 46

Companion cells are usually associated with

  1. AOption (a)

    Phloem fibres

  2. BOption (b)

    Vessels

  3. COption (c)

    Tracheids 

  4. DOption (d)

    Sieve tubes

View answer & explanation

Correct answer

Answer: (d)D.

Sieve tubes

Why this answer is correct

The correct answer is - Sieve tubes

Key Points

  • Sieve tubes
  • Companion cells are specialized parenchymatous cells that are closely associated with sieve tube elements in the phloem of angiosperms.
  • The sieve tube elements and companion cells are connected by pit fields present between their common longitudinal walls.
  • A unique feature is that both the sieve tube element and its associated companion cell help in the conduction of food (sucrose) throughout the plant.
  • Functional Relationship
  • Sieve tube elements lack a nucleus at maturity; therefore, the functions of sieve tubes are controlled by the nucleus of the companion cells.
  • Companion cells help in maintaining the pressure gradient in the sieve tubes, which is essential for the transport of organic nutrients.

Additional Information

  • Phloem Components
  • Phloem is a complex tissue composed of four types of cells: Sieve tube elements, Companion cells, Phloem parenchyma, and Phloem fibres.
  • In Gymnosperms, companion cells are absent; instead, they possess albuminous cells (also known as Strasburger cells) which perform similar functions.
  • Xylem Components
  • Tracheids and Vessels are the primary water-conducting elements of the xylem, not the phloem.
  • Xylem is responsible for the transport of water and minerals from roots to the upper parts of the plant.
  • Phloem Fibres
  • Also known as bast fibres, these are made up of sclerenchymatous cells and provide mechanical strength to the plant.
  • They are generally absent in the primary phloem but found in the secondary phloem.

Question 47

Who divided Dicotyledanes into lignosae and Herbaceae ?

  1. AOption (a)

    Takhtajan

  2. BOption (b)

    Cronquist

  3. COption (c)

    Hutchinson

  4. DOption (d)

    Bentham and Hooker

View answer & explanation

Correct answer

Answer: (c)C.

Hutchinson

Why this answer is correct

The correct answer is - Hutchinson

Key Points

  • John Hutchinson
  • John Hutchinson (1884–1972) was a renowned British botanist who proposed a phylogenetic system of classification.
  • In his major work, The Families of Flowering Plants, he divided the Dicotyledones into two distinct evolutionary lines based on their growth habit: Lignosae and Herbaceae.
  • Lignosae: This group consists of primarily woody plants (trees and shrubs), starting with the primitive Magnoliaceae.
  • Herbaceae: This group consists of primarily herbaceous plants, starting with the family Ranunculaceae.

Additional Information

  • Hutchinson's Classification Principles
  • His system was based on 24 phylogenetic principles, where he considered woody plants to be more primitive than herbaceous ones.
  • While influential, his division of Dicots into Lignosae and Herbaceae was criticized for separating closely related families based solely on habit.
  • Bentham and Hooker
  • They proposed a natural system of classification in their book Genera Plantarum. They divided Dicots into Polypetalae, Gamopetalae, and Monochlamydeae.
  • Takhtajan and Cronquist
  • Both Armen Takhtajan and Arthur Cronquist proposed modern phylogenetic systems.
  • Takhtajan considered the Magnoliales as the most primitive group of flowering plants, but he did not use the Lignosae/Herbaceae split as a primary classification criteria like Hutchinson.

Question 48

Bicarpellary, syncarpous, superior ovary with gynobasis style are characteristic features of

  1. AOption (a)

    Solanaceae

  2. BOption (b)

    Brassicaceae

  3. COption (c)

    Acanthaceae

  4. DOption (d)

    Lamiaceae

View answer & explanation

Correct answer

Answer: (d)D.

Lamiaceae

Why this answer is correct

The correct answer is - Lamiaceae

Key Points

  • Lamiaceae (Labiatae)
  • The family Lamiaceae is distinguished by a bicarpellary (two carpels), syncarpous (fused carpels), and superior ovary.
  • The most characteristic feature is the gynobasic style, where the style originates from the base of the ovary, specifically between the four lobes.
  • The ovary in this family is typically deeply four-lobed due to the formation of a false septum, and the fruit is usually a group of four nutlets.

Additional Information

  • Solanaceae
  • Flowers are bicarpellary and syncarpous with a superior ovary, but the style is terminal (arising from the top of the ovary).
  • The ovary is usually placed obliquely in the flower.
  • Brassicaceae
  • Characterized by a bicarpellary, syncarpous, superior ovary that is initially unilocular but becomes bilocular due to a false septum called the replum.
  • The style is terminal.
  • Acanthaceae
  • Features a bicarpellary, syncarpous, superior ovary with axile placentation and a terminal style.
  • Gynobasic Style
  • It is a rare botanical condition where the style is attached to the receptacle at the base of the ovary lobes.
  • Apart from Lamiaceae, it is also a characteristic feature of the Boraginaceae family.

Question 49

Colletotrichum infecting sugarcane produces asexual fruiting bodies known as

  1. AOption (a)

    Sporodochium

  2. BOption (b)

    Acervulus

  3. COption (c)

    Synnemata

  4. DOption (d)

    Pycnidia

View answer & explanation

Correct answer

Answer: (b)B.

Acervulus

Why this answer is correct

The correct answer is - Acervulus

Key Points

  • Acervulus
  • The fungus Colletotrichum, which causes diseases like red rot in sugarcane, produces asexual spores in a fruiting body known as an Acervulus.
  • An acervulus is a saucer-shaped, subepidermal asexual fruiting body that eventually erupts through the host epidermis to release spores.
  • It consists of a thin layer of fungal tissue (stroma) from which short, closely packed conidiophores arise to produce conidia.
  • A characteristic feature of the acervulus in Colletotrichum is the presence of setae, which are dark-colored, stiff, hair-like structures interspersed among the conidiophores.

Additional Information

  • Red Rot of Sugarcane
  • This disease is specifically caused by Colletotrichum falcatum.
  • Symptoms include reddening of the internal pith tissues with characteristic white transverse patches and a sour alcoholic smell.
  • Types of Asexual Fruiting Bodies
  • Pycnidia: These are flask-shaped structures with a small opening called an ostiole at the top through which spores are discharged (e.g., Phoma, Septoria).
  • Sporodochium: A cushion-like mass of fungal tissue that breaks through the host surface, bearing short, branched conidiophores (e.g., Fusarium).
  • Synnemata: A structure formed by a bundle of upright, fused conidiophores that bear spores at their tips or along their sides (e.g., Graphium).

Question 50

The apophysis in moss is

  1. AOption (a)

     Basal part of capsule

  2. BOption (b)

    Central part of capsule

  3. COption (c)

    Leaves surrounding sex organs

  4. DOption (d)

    Sterile unisexual structures surrounding antheridia

View answer & explanation

Correct answer

Answer: (a)A.

 Basal part of capsule

Why this answer is correct

The correct answer is - Basal part of capsule

Key Points

  • Apophysis
  • The apophysis is the basal sterile region of the capsule in mosses (such as Funaria).
  • It is the part of the capsule that is continuous with the seta.
  • The apophysis is characterized by the presence of stomata and chloroplasts, making it the primary site for photosynthesis within the sporophyte.
  • It acts as a neck-like structure connecting the conducting tissue of the seta to the fertile region of the capsule.

Additional Information

  • Structure of Moss Capsule
  • The capsule is the spore-bearing part of the moss sporophyte and is generally divided into three parts:
  • Apophysis: The lower sterile photosynthetic zone.
  • Theca: The middle fertile zone containing the spore sac and columella.
  • Operculum: The terminal lid that opens to facilitate spore dispersal.
  • The Moss Sporophyte
  • The sporophyte develops from the zygote and consists of a foot, seta, and capsule.
  • While it is partially dependent on the gametophyte for water and minerals, the presence of the apophysis allows the sporophyte to manufacture some of its own food.
  • Other Structures
  • Paraphyses: These are the sterile hair-like structures (often unisexual) found surrounding the antheridia or archegonia.
  • Perichaetial leaves: These are the specialized leaves that surround the sex organs in mosses.

Question 51

Aecial cups are found on the

  1. AOption (a)

    upper surface of barbery leaves

  2. BOption (b)

     lower surface of wheat leaves

  3. COption (c)

    lower surface of barbery leaves

  4. DOption (d)

    upper surface of wheat leaves

View answer & explanation

Correct answer

Answer: (c)C.

lower surface of barbery leaves

Why this answer is correct

The correct answer is - lower surface of barbery leaves

Key Points

  • Aecial Cups (Aecia)
  • Aecial cups are cup-shaped fruiting bodies produced during the life cycle of the rust fungus Puccinia graminis (Black stem rust).
  • These structures are specifically found on the lower surface (abaxial surface) of the leaves of the barberry plant (Berberis vulgaris).
  • Inside these cups, aeciospores are produced in chains. These spores are dikaryotic (n+n) and are responsible for transmitting the infection from the alternate host (barberry) to the primary host (wheat).

Additional Information

  • Lifecycle of Puccinia graminis
  • Puccinia graminis is heteroecious, meaning it requires two different hosts to complete its life cycle: Wheat (Primary host) and Barberry (Alternate host).
  • The lifecycle consists of five stages:
  • Stage 0: Pycnia (Spermogonia) - Produced on the upper surface of barberry leaves.
  • Stage I: Aecia - Produced on the lower surface of barberry leaves.
  • Stage II: Uredinia - Produced on wheat plants (Red rust stage).
  • Stage III: Telia - Produced on wheat plants (Black rust stage).
  • Stage IV: Basidia - Produced by the germination of teliospores, producing basidiospores that infect barberry.
  • Host Specificity
  • While the Pycnia and Aecia are found on barberry, the Uredinia and Telia are found on wheat.
  • Aeciospores cannot re-infect barberry leaves; they must land on a wheat plant to continue the lifecycle.

Question 52

Retort cells are found in

  1. AOption (a)

    Equisetum stem

  2. BOption (b)

    Selaginella leaves

  3. COption (c)

    Sphagnum leaves

  4. DOption (d)

    Sphagnum stem

View answer & explanation

Correct answer

Answer: (d)D.

Sphagnum stem

Why this answer is correct

The correct answer is - Sphagnum stem

Key Points

  • Retort Cells
  • In the bryophyte Sphagnum (Peat moss), the outer layer or cortex of the lateral branches contains specialized cells.
  • Some of these cortical cells become enlarged and bottle-shaped with a distinct neck and an opening (pore) at the top; these are called retort cells.
  • These cells are dead, hyaline, and function primarily in water storage and transport through capillary action.

Additional Information

  • Sphagnum (Peat Moss)
  • Sphagnum belongs to the class Sphagnopsida. It is commonly found in bogs and marshes.
  • The leaves of Sphagnum are unique as they consist of two types of cells:
  • Chlorophyllose cells: Small, living, green cells that perform photosynthesis.
  • Hyaline cells: Large, dead, diamond-shaped cells that store huge amounts of water.
  • Due to its incredible water-retaining capacity, Sphagnum is used as packing material for trans-shipment of living plants and flowers.
  • Other Options
  • Equisetum (Horsetail): A pteridophyte characterized by a jointed stem containing silica. It does not possess retort cells.
  • Selaginella: A lycophyte (pteridophyte) known for its heterosporous nature and 'resurrection' habit in some species; it lacks retort cells.

Question 53

Which type of stele is found in fern rhizome ?

  1. AOption (a)

    Actinostele

  2. BOption (b)

    Dictyostele

  3. COption (c)

    Haplostele

  4. DOption (d)

    Solenostele

View answer & explanation

Correct answer

Answer: (b)B.

Dictyostele

Why this answer is correct

The correct answer is - Dictyostele

Key Points

  • Dictyostele
  • In the rhizomes of ferns (such as Dryopteris and Pteris), the vascular cylinder is typically a Dictyostele.
  • A dictyostele is a modified siphonostele where the vascular tissue is divided into several discrete strands due to the presence of numerous overlapping leaf gaps.
  • Each individual vascular strand in a dictyostele is known as a meristele.
  • Each meristele is functionally independent, surrounded by its own endodermis and pericycle.

Additional Information

  • Types of Stele
  • Protostele: The most primitive type of stele where the vascular tissue forms a solid core without a central pith.
  • Haplostele: A protostele with a smooth, cylindrical core of xylem (e.g., Rhynia).
  • Actinostele: A protostele where the central xylem core is star-shaped or has radiating ribs (e.g., Lycopodium serratum).
  • Siphonostele: A stele that contains a central pith.
  • Solenostele: A siphonostele with non-overlapping leaf gaps, meaning only one leaf gap is visible in a single transverse section (e.g., Adiantum).
  • Significance of Leaf Gaps
  • Leaf gaps are parenchymatous regions in the vascular cylinder found immediately above the point where a leaf trace departs.
  • The complexity of the stele often correlates with the evolutionary advancement of the plant group.

Question 54

The point of attachment of ovule to funiculus is known as

  1. AOption (a)

    Chalaza

  2. BOption (b)

    Hilum

  3. COption (c)

    Nucellus

  4. DOption (d)

    Placenta

View answer & explanation

Correct answer

Answer: (a)A.

Chalaza

Why this answer is correct

The correct answer is - Hilum

Key Points

  • Hilum
  • The hilum is the point where the ovule is attached to the funiculus, which is a stalk-like structure connecting the ovule to the ovary wall.
  • It serves as the junction between the ovule and its supporting tissue, playing a critical role in nutrient and water transport.
  • This region is identifiable as a scar or mark on the seed after fertilization and seed maturation.

Additional Information

  • Ovule structure
  • The ovule comprises key regions: nucellus, integuments, chalaza, and hilum.
  • Chalaza is the base of the ovule where the integuments and nucellus meet. It is not involved in attachment.
  • Nucellus is the central tissue of the ovule, responsible for nourishing the developing embryo sac.
  • Placenta
  • The placenta is the tissue in the ovary where ovules are attached, but it is distinct from the hilum.
  • It ensures the ovule's positioning within the ovary and supports nutrient transport.

Question 55

Photorespiration occurs in:

  1. AOption (a)

    Mitochondria and chloroplasts

  2. BOption (b)

    Peroxisomes and chloroplasts

  3. COption (c)

    Mitochondria, chloroplasts, and peroxisomes

  4. DOption (d)

    None of these

View answer & explanation

Correct answer

Answer: (c)C.

Mitochondria, chloroplasts, and peroxisomes

Why this answer is correct

Correct Answer – Mitochondria, Chloroplasts and Peroxisomes

Key Points

  • Photorespiration
  • Photorespiration, also known as the C₂ cycle, is a light-dependent process in which oxygen is consumed and carbon dioxide is released.
  • This process is specifically completed with the coordination of three cell organelles: Chloroplast, Peroxisome, and Mitochondrion.
  • It mainly occurs in C3 plants when the concentration of CO₂ in the atmosphere is low and the concentration of O₂ is high.

Additional Information 

 

  • Role of Organelles
  • Chloroplast: Here, the RuBisCO enzyme combines with oxygen to form 3-PGA and 2-phosphoglycolate.
  • Peroxisome: Here, glycolate is oxidized and converted into glycine (an amino acid).
  • Mitochondria: Here, two molecules of glycine combine to form serine, and CO2 is released.
  • महत्व
  • t is considered a wasteful process because it neither produces energy (ATP) nor synthesizes sugars.
  • This process is absent in C4 plants, which is one of the reasons for their high productivity

Question 56

Pheophytin is

  1. AOption (a)

    Chlorophyll a

  2. BOption (b)

    Chlorophyll b

  3. COption (c)

    Xanthophyll

  4. DOption (d)

    Chlorophyll without magnesium

View answer & explanation

Correct answer

Answer: (d)D.

Chlorophyll without magnesium

Why this answer is correct

The correct answer is - Chlorophyll without magnesium

Key Points

  • Pheophytin
  • Pheophytin is a chemical compound that serves as the first electron carrier intermediate in the electron transfer pathway of Photosystem II (PS II).
  • Structurally, it is essentially a chlorophyll molecule that lacks the central magnesium (Mg²⁺) ion.
  • In the porphyrin-like ring of a standard chlorophyll molecule, the central magnesium is replaced by two hydrogen atoms to form pheophytin.
  • It plays a crucial role in the primary photochemical act of photosynthesis by accepting an electron from the excited reaction center.

Additional Information

  • Role in Electron Transport
  • In the Z-scheme of light reactions, the reaction center P680 transfers an electron to pheophytin upon excitation by light.
  • Pheophytin then passes this electron to Plastoquinone (QA), initiating the flow of electrons through the transport chain.
  • Types of Pheophytin
  • Just as there are Chlorophyll a and b, there are corresponding forms: Pheophytin a and Pheophytin b.
  • Pheophytin a is the specific primary electron acceptor found in the reaction center of PS II.
  • Chlorophyll vs. Pheophytin
  • Chlorophyll: Contains a magnesium ion; functions in light absorption and energy transfer.
  • Pheophytin: Lacks magnesium; functions specifically as a redox-active component in the electron transport chain.
  • The removal of magnesium from chlorophyll is an early step in the natural degradation of chlorophyll during leaf senescence.

Question 57

Zymase enzyme was discovered by

  1. AOption (a)

    Pasteur

  2. BOption (b)

    Buchner

  3. COption (c)

    Hill

  4. DOption (d)

    Altman

View answer & explanation

Correct answer

Answer: (b)B.

Buchner

Why this answer is correct

The correct answer is - Buchner

Key Points

  • Eduard Buchner
  • The enzyme Zymase was discovered by the German chemist Eduard Buchner in 1897.
  • He demonstrated that fermentation could occur in cell-free extracts of yeast, proving that living yeast cells were not strictly necessary for the process.
  • This discovery was monumental as it bridged the gap between chemistry and biology, leading to the birth of biochemistry.
  • Buchner received the Nobel Prize in Chemistry in 1907 for his biochemical researches and his discovery of cell-free fermentation.

Additional Information

  • Louis Pasteur
  • Pasteur is known for his work on pasteurization and germ theory.
  • He believed that fermentation was a vital process that could only be performed by living cells (vitalism).
  • Robert Hill
  • Robert Hill is famous for discovering the Hill Reaction in 1937.
  • This reaction represents the light-dependent stage of photosynthesis, where oxygen is evolved in the presence of an electron acceptor.
  • Richard Altmann
  • Altmann was a pathologist who is credited with the discovery of mitochondria (which he named bioblasts) in 1890.
  • He also coined the term nucleic acid in 1889.

Question 58

The first stable product formed after CO2 fixation in C4 plants is

  1. AOption (a)

    Oxalo-acetic acid

  2. BOption (b)

    Malic acid

  3. COption (c)

    Aspartic acid

  4. DOption (d)

     Phosphoglyceric acid

View answer & explanation

Correct answer

Answer: (a)A.

Oxalo-acetic acid

Why this answer is correct

The correct answer is - Oxalo-acetic acid

Key Points

  • CO2 fixation in C4 plants
  • In C4 plants, the first step of carbon fixation occurs in the mesophyll cells.
  • The enzyme PEP carboxylase catalyzes the reaction between phosphoenolpyruvate (PEP) and CO2.
  • This results in the formation of the four-carbon compound Oxalo-acetic acid (OAA), which is the first stable product.
  • Why Oxalo-acetic acid is the first stable product
  • Unlike C3 plants, where the first product is a three-carbon compound (phosphoglyceric acid), C4 plants produce a four-carbon compound to efficiently capture CO2.
  • This mechanism is an adaptation to reduce photorespiration, especially in plants growing in hot and dry climates.

Additional Information

  • C4 pathway overview
  • The C4 pathway involves two distinct types of cells: mesophyll cells and bundle sheath cells.
  • After the formation of oxalo-acetic acid in mesophyll cells, it is converted into malic acid or aspartic acid for transport to bundle sheath cells.
  • In the bundle sheath cells, CO2 is released and enters the Calvin cycle for sugar synthesis.
  • Advantages of the C4 pathway
  • Minimizes photorespiration, which is a wasteful process in C3 plants.
  • Enhances water-use efficiency, making it ideal for plants in arid and semi-arid conditions.
  • Examples of C4 plants include maize, sugarcane, and sorghum.

Question 59

Molecule which donates energy during elongation of polypeptide chain is

  1. AOption (a)

    ATP

  2. BOption (b)

    ADP

  3. COption (c)

    GTP

  4. DOption (d)

    CTP

View answer & explanation

Correct answer

Answer: (a)A.

ATP

Why this answer is correct

The correct answer is - GTP

Key Points

  • GTP
  • GTP (Guanosine Triphosphate) is the primary molecule that donates energy during the elongation of the polypeptide chain in protein synthesis.
  • During elongation, GTP is hydrolyzed to GDP, providing the energy required for the translocation of the ribosome and attachment of the aminoacyl-tRNA to the A-site.
  • This process ensures the proper addition of amino acids in sequence to form the growing polypeptide chain.

Additional Information

  • Role of GTP in Translation
  • In translation, GTP is used by elongation factors such as EF-Tu and EF-G in prokaryotes, and eEF1 and eEF2 in eukaryotes.
  • EF-Tu facilitates the delivery of aminoacyl-tRNA to the ribosome, while EF-G is involved in ribosomal translocation.
  • Comparison with ATP
  • While ATP is essential for charging tRNA with amino acids during the activation phase, GTP is specifically required during the elongation phase.
  • Both molecules act as energy sources but have distinct roles in protein synthesis.

Question 60

Which one of the following is generally considered as rooting hormone ?

  1. AOption (a)

    Auxin

  2. BOption (b)

    Gibberellin

  3. COption (c)

    Cytokinin

  4. DOption (d)

    Abscisic acid

View answer & explanation

Correct answer

Answer: (a)A.

Auxin

Why this answer is correct

The correct answer is - Auxin

Key Points

  • Auxin
  • Auxins are a class of plant hormones that are widely known as rooting hormones because they stimulate the initiation of adventitious roots in stem cuttings.
  • They play a major role in regulating plant growth processes such as cell elongation, apical dominance, and root development.
  • In horticulture and agriculture, synthetic auxins like Indole-3-butyric acid (IBA) and Naphthaleneacetic acid (NAA) are commonly used in rooting powders to help plants propagate from cuttings.

Additional Information

  • Gibberellin
  • Gibberellins are primarily responsible for stem elongation, bolting in rosette plants, and breaking seed dormancy.
  • They help in the mobilization of nutrients during seed germination.
  • Cytokinin
  • Cytokinins promote cell division (cytokinesis) and are essential for shoot formation and delaying leaf senescence.
  • In tissue culture, a high cytokinin-to-auxin ratio promotes the development of shoots.
  • Abscisic acid (ABA)
  • ABA is often called the stress hormone as it helps plants respond to environmental stresses like drought.
  • It inhibits growth, promotes seed dormancy, and triggers the closing of stomata to prevent water loss.

Question 61

Which of the following is a base analogue of DNA?

  1. AOption (a)

    5-bromouracil

  2. BOption (b)

    Ethyl methane sulphonate

  3. COption (c)

    Nitroso-guanidine

  4. DOption (d)

    Thymine pyrophosphate

View answer & explanation

Correct answer

Answer: (a)A.

5-bromouracil

Why this answer is correct

The correct answer is - 5-bromouracil

Key Points

  • 5-bromouracil
  • 5-bromouracil (5-BU) is a chemical mutagen that acts as a base analogue of thymine.
  • A base analogue is a chemical compound that has a similar structure to one of the four standard nitrogenous bases (adenine, guanine, cytosine, or thymine) in DNA.
  • Because of its structural similarity, it can be incorporated into DNA during replication in place of the normal base.
  • 5-BU contains a bromine atom at the carbon-5 position instead of the methyl group found in thymine.

Additional Information

  • Mechanism of Mutagenesis
  • 5-bromouracil can exist in two tautomeric forms: the keto form and the enol form.
  • In its common keto form, it pairs with adenine. However, when it shifts to its rare enol form, it pairs with guanine.
  • This mispairing results in transition mutations, where an A-T base pair is eventually replaced by a G-C base pair.
  • Alkylating Agents
  • Ethyl methane sulphonate (EMS) and Nitroso-guanidine are examples of alkylating agents.
  • These chemicals induce mutations by adding alkyl groups (like methyl or ethyl) to the DNA bases, leading to altered base-pairing properties, but they are not base analogues.
  • Other Base Analogues
  • Another common base analogue is 2-aminopurine (2-AP), which is an analogue of adenine and can pair with thymine or cytosine.

Question 62

Polylinker DNA is one which

  1. AOption (a)

    do not code any protein.

  2. BOption (b)

    has restriction sites for several enzymes.

  3. COption (c)

    is used for D.N.A. transfer.

  4. DOption (d)

    None of the above

View answer & explanation

Correct answer

Answer: (b)B.

has restriction sites for several enzymes.

Why this answer is correct

The correct answer is - has restriction sites for several enzymes

Key Points

  • Polylinker DNA
  • A polylinker, also commonly referred to as a Multiple Cloning Site (MCS), is a short segment of DNA containing several restriction enzyme recognition sites.
  • These sites are typically unique, meaning they occur only once within the entire vector (plasmid), which prevents the vector from being cut into multiple pieces.
  • The primary purpose of a polylinker is to allow a piece of foreign DNA to be inserted into the vector using one or two specific restriction enzymes.

Additional Information

  • Role in Recombinant DNA Technology
  • Polylinkers are essential components of cloning vectors (like pUC19 or pBR322) used in genetic engineering.
  • They provide flexibility because a single vector can be used to clone DNA fragments generated by many different restriction endonucleases.
  • Location and Screening
  • In many modern vectors, the polylinker is located within a reporter gene, such as the lacZ gene.
  • When a foreign DNA fragment is inserted into the polylinker, it disrupts the reporter gene (insertional inactivation), allowing researchers to identify successful clones through methods like blue-white screening.
  • Restriction Endonucleases
  • These are enzymes that cut DNA at specific palindromic sequences.
  • By having multiple such sites clustered in one area (the polylinker), scientists can perform directional cloning by using two different enzymes to cut both the vector and the insert.

Question 63

Which of the following chromosomes is most stable ?

  1. AOption (a)

    Polycentric

  2. BOption (b)

    Acentric

  3. COption (c)

    Monocentric

  4. DOption (d)

    Dicentric

View answer & explanation

Correct answer

Answer: (c)C.

Monocentric

Why this answer is correct

The correct answer is - Monocentric

Key Points

  • Monocentric Chromosomes
  • A monocentric chromosome is a chromosome that possesses only one centromere.
  • This is the most stable form of chromosome because it allows for a single, coordinated point of attachment for spindle fibers (microtubules) during cell division.
  • The presence of a single centromere ensures that sister chromatids are pulled accurately to opposite poles during mitosis and meiosis, preventing chromosome breakage or loss.

Additional Information

  • Unstable Chromosome Types
  • Acentric Chromosomes: These lack a centromere entirely. Without a centromere, they cannot attach to spindle fibers and are usually lost during cell division, making them highly unstable.
  • Dicentric Chromosomes: These have two centromeres. If the two centromeres are pulled toward opposite poles during anaphase, the chromosome forms a bridge and eventually breaks, leading to genomic instability.
  • Polycentric Chromosomes: These have multiple centromeres. Similar to dicentric chromosomes, they are generally unstable in most organisms because they risk being pulled in multiple directions simultaneously, leading to fragmentation.
  • Centromere Function
  • The centromere is the specialized DNA sequence that links a pair of sister chromatids.
  • It is the site where the kinetochore forms, which is essential for the attachment of spindle microtubules.
  • Stability of the genome across generations relies heavily on the precise functioning and singular nature of the centromere in monocentric organisms.

Question 64

Nucleosome, a structural unit of all chromosomes is made up of

  1. AOption (a)

    RNA + Protein

  2. BOption (b)

    DNA + Histone protein

  3. COption (c)

    DNA + RNA + Histone protein

  4. DOption (d)

    None of the above

View answer & explanation

Correct answer

Answer: (b)B.

DNA + Histone protein

Why this answer is correct

The correct answer is - DNA + Histone protein

Key Points

  • Nucleosome Composition
  • A nucleosome is the fundamental subunit of chromatin, which makes up eukaryotic chromosomes.
  • It consists of a segment of DNA wrapped around a core of histone proteins.
  • The core particle is made up of eight histone molecules (an octamer) around which the DNA wraps approximately 1.65 times.

Additional Information

  • Histone Proteins
  • Histones are highly alkaline proteins that are positively charged.
  • The histone octamer consists of two copies each of the core histones: H2A, H2B, H3, and H4.
  • Because DNA is negatively charged (due to phosphate groups), it binds tightly to the positively charged histones.
  • Beads-on-a-string Structure
  • Under an electron microscope, chromatin in its extended form looks like beads-on-a-string, where the beads are nucleosomes and the string is the linker DNA.
  • The H1 histone is often referred to as the linker histone, as it binds to the linker DNA to help stabilize the structure.
  • Function of Nucleosomes
  • The primary function of nucleosomes is to package the massive length of DNA into a compact structure that can fit within the cell nucleus.
  • This packaging also plays a critical role in regulating gene expression and protecting DNA from damage.

Question 65

The common wheat (Triticum aestivum) is a/an

  1. AOption (a)

    Hexaploid species

  2. BOption (b)

    Octaploid species

  3. COption (c)

    Diploid species

  4. DOption (d)

    Aneuploid species

View answer & explanation

Correct answer

Answer: (a)A.

Hexaploid species

Why this answer is correct

The correct answer is - Hexaploid species

Key Points

  • Hexaploid Nature
  • Common bread wheat (Triticum aestivum) is a hexaploid species, meaning it contains six sets of chromosomes.
  • The chromosomal constitution is represented as 2n = 6x = 42.
  • It is specifically an allohexaploid, containing three distinct genomes (A, B, and D) derived from three different diploid ancestral species.

Additional Information

  • Evolutionary Ancestry
  • The A genome was contributed by the diploid wild wheat Triticum urartu.
  • The B genome is thought to have come from a species closely related to Aegilops speltoides.
  • The D genome was contributed by Aegilops tauschii (goat grass).
  • Polyploidy in Wheat
  • Diploid wheat: (e.g., Triticum monococcum) has 14 chromosomes (2n=14).
  • Tetraploid wheat: (e.g., Triticum durum, used for pasta) has 28 chromosomes (2n=28) with the genome AABB.
  • Hexaploid wheat: (Triticum aestivum) has 42 chromosomes (2n=42) with the genome AABBDD.
  • Importance of Hexaploidy
  • Hexaploidy provides common wheat with a large genetic buffer, allowing it to adapt to various environmental conditions across the globe.
  • The addition of the D genome significantly improved the baking quality and dough elasticity of the wheat.

Question 66

Which one of the following organelles is not present in Prokaryotes?

  1. AOption (a)

    Ribosome

  2. BOption (b)

    Mesosome

  3. COption (c)

    Flagella

  4. DOption (d)

    Endoplasmic reticulum

View answer & explanation

Correct answer

Answer: (d)D.

Endoplasmic reticulum

Why this answer is correct

The correct answer is - Endoplasmic reticulum

Key Points

  • Endoplasmic Reticulum (ER)
  • The Endoplasmic reticulum is a membrane-bound organelle that forms a network of tubules and sacs within Eukaryotic cells.
  • Prokaryotes are characterized by the absence of a membrane-bound nucleus and other membrane-bound organelles, including the ER, Golgi apparatus, and mitochondria.
  • In prokaryotic cells, functions that would occur in the ER (like protein and lipid synthesis) take place in the cytoplasm or at the plasma membrane.

Additional Information

  • Structures Present in Prokaryotes
  • Ribosomes: Prokaryotes contain 70S ribosomes, which are smaller than the 80S ribosomes found in eukaryotes. They are essential for protein synthesis.
  • Mesosome: These are folds or invaginations of the plasma membrane in prokaryotes. They play a vital role in cell wall formation, DNA replication, and cellular respiration.
  • Flagella: Many prokaryotes have flagella used for locomotion. However, the prokaryotic flagellum is structurally simpler than the eukaryotic one, being made of the protein flagellin.
  • Key Differences
  • Prokaryotic Cells: No nuclear membrane, 70S ribosomes, generally smaller in size, lack complex organelles (e.g., Bacteria, Archaea).
  • Eukaryotic Cells: Distinct nucleus with nuclear membrane, 80S ribosomes, larger and more complex with organelles like Endoplasmic reticulum and mitochondria (e.g., Plants, Animals, Fungi).

Question 67

Which of the following techniques is used to locate R.N.A. on a gel?

  1. AOption (a)

    Northern blotting

  2. BOption (b)

    Southern blotting

  3. COption (c)

    Western blotting

  4. DOption (d)

    Eastern blotting

View answer & explanation

Correct answer

Answer: (a)A.

Northern blotting

Why this answer is correct

The correct answer is - Northern blotting

Key Points

  • Northern Blotting
  • Northern blotting is a molecular biology technique used to detect specific RNA sequences within a complex mixture of RNA.
  • The process involves separating RNA fragments by size using gel electrophoresis and then transferring them to a carrier membrane (usually nitrocellulose or nylon).
  • Once transferred, the RNA is identified using a hybridization probe (a labeled strand of DNA or RNA) that is complementary to the target RNA sequence.
  • It is widely used to study gene expression by measuring the amount and size of specific mRNA molecules in different tissues or under different conditions.

Additional Information

  • Southern Blotting
  • Named after Edwin Southern, this technique is used for the detection of specific DNA sequences in DNA samples.
  • Western Blotting
  • This technique is used to identify specific proteins. It uses antibodies to bind to the target protein after it has been separated by electrophoresis and transferred to a membrane.
  • Eastern Blotting
  • An extension of biochemical techniques used to detect post-translational modifications of proteins, such as lipids, phosphates, or glycoconjugates.
  • Summary of Blotting Techniques
  • Southern - DNA
  • Northern - RNA
  • Western - Protein
  • (A common mnemonic is SNOW DROP: Southern-DNA, Northern-RNA, Western-Protein).

Question 68

Polycentric chromosomes are found in

  1. AOption (a)

    Oenothera

  2. BOption (b)

    Trillium

  3. COption (c)

    Drosophila

  4. DOption (d)

    Luzula

View answer & explanation

Correct answer

Answer: (a)A.

Oenothera

Why this answer is correct

The correct answer is - Oenothera

Key Points

  • Polycentric chromosomes
  • These chromosomes have multiple centromeres instead of just one.
  • They are observed in certain plant species, particularly in the genus Oenothera.
  • The multiple centromeres provide structural and functional stability during cell division, ensuring proper segregation.
  • Polycentric chromosomes are rare and are primarily studied in genetic research focusing on chromosomal behavior.

Additional Information

  • Chromosomal types
  • Monocentric chromosomes:
  • Contain a single centromere.
  • Found in most eukaryotic organisms.
  • Polycentric chromosomes:
  • Contain multiple centromeres.
  • Less common, observed in specific genera like Oenothera.
  • Centromere function
  • Serves as the attachment point for spindle fibers during mitosis and meiosis.
  • Ensures proper distribution of chromosomes to daughter cells.

Question 69

Which one of the following histones is arginine rich?

  1. AOption (a)

    H - 1

  2. BOption (b)

    H - 2A

  3. COption (c)

    H - 2B

  4. DOption (d)

    H - 3

View answer & explanation

Correct answer

Answer: (a)A.

H - 1

Why this answer is correct

The correct answer is - H - 1

Key Points

  • Histone H-1
  • H-1 is a linker histone that binds to nucleosomes and stabilizes the structure of chromatin.
  • Arginine-rich nature is a key characteristic of H-1, contributing to its ability to interact with negatively charged DNA.
  • This specific property plays an essential role in chromatin condensation during processes like gene regulation and cell division.
  • Function
  • H-1 helps in maintaining the higher-order structure of chromatin by binding between adjacent nucleosomes.
  • Its positive charge due to the presence of arginine facilitates interaction with the negatively charged phosphate backbone of DNA.

Additional Information

  • Histone Types
  • Histones are basic proteins found in eukaryotic cells, classified into core histones (H-2A, H-2B, H-3, and H-4) and linker histones (H-1).
  • Core histones form the nucleosome structure, while linker histones like H-1 help in stabilizing chromatin.
  • Arginine and DNA Interaction
  • Arginine is a positively charged amino acid, enabling histones to bind effectively to DNA.
  • This binding is crucial for processes like gene expression regulation and chromatin remodeling.
  • Role in Gene Regulation
  • Histone modifications, including those on H-1, influence epigenetic regulation of genes.
  • Such modifications impact processes like transcription, replication, and DNA repair.

Question 70

Smallest, non-membranous cytoplasmic organelles are

  1. AOption (a)

    Lysosomes

  2. BOption (b)

    Ribosomes

  3. COption (c)

    Peroxisomes

  4. DOption (d)

    a) and (b) both

View answer & explanation

Correct answer

Answer: (b)B.

Ribosomes

Why this answer is correct

The correct answer is - Ribosomes

Key Points

  • Ribosomes
  • Ribosomes are considered the smallest organelles present within the cell.
  • They are non-membranous cytoplasmic organelles, meaning they are not surrounded by a phospholipid bilayer.
  • They are found in both prokaryotic and eukaryotic cells, emphasizing their fundamental role in life.
  • Structurally, they are composed of two subunits made of ribosomal RNA (rRNA) and proteins.

Additional Information

  • Types of Organelles
  • Non-membranous Organelles: These include Ribosomes, Centrioles, and the Nucleolus. These are not bound by any membrane.
  • Single Membrane-bound Organelles: Organelles like Lysosomes, Peroxisomes, Vacuoles, and the Endoplasmic Reticulum are enclosed by a single unit membrane.
  • Double Membrane-bound Organelles: Mitochondria, Chloroplasts, and the Nucleus are enclosed by two membranes.
  • Function of Ribosomes
  • They are known as the protein factories of the cell because they are the site where translation (protein synthesis) occurs.
  • Discovery
  • Ribosomes were first identified as dense particles under an electron microscope by George Palade in 1953, which is why they are sometimes called Palade particles.

Question 71

The transfer of pollen grains from another of a flower to the stigma of different flower of same plant is called

  1. AOption (a)

    Autogamy

  2. BOption (b)

    Allogamy

  3. COption (c)

    Geitonogamy

  4. DOption (d)

    Xenogamy

View answer & explanation

Correct answer

Answer: (c)C.

Geitonogamy

Why this answer is correct

The correct answer is - Geitonogamy

Key Points

  • Geitonogamy
  • It is the transfer of pollen grains from the anther to the stigma of another flower of the same plant.
  • Although geitonogamy is functionally cross-pollination involving a pollinating agent, genetically it is similar to autogamy since the pollen grains come from the same plant.
  • This process relies on external agents like insects, wind, or water to carry the pollen, yet the resulting offspring are genetically identical to the parent.

Additional Information

  • Autogamy
  • In this type, pollination is achieved within the same flower.
  • Transfer of pollen grains from the anther to the stigma of the same flower.
  • Common in plants like Viola (common pansy), Oxalis, and Commelina.
  • Xenogamy
  • Transfer of pollen grains from anther to the stigma of a different plant.
  • This is the only type of pollination which during pollination brings genetically different types of pollen grains to the stigma.
  • Pollinating Agents
  • Plants use two abiotic (wind and water) and one biotic (animals/insects) agents to achieve pollination.
  • Majority of plants use biotic agents for pollination.

Question 72

A vascular bundle in which xylem surrounds phloem is called

  1. AOption (a)

    Amphicribal

  2. BOption (b)

    Amphivasal

  3. COption (c)

    Radial

  4. DOption (d)

    Conjoint and collateral

View answer & explanation

Correct answer

Answer: (b)B.

Amphivasal

Why this answer is correct

The correct answer is - Amphivasal

Key Points

  • Amphivasal
  • In an Amphivasal vascular bundle, the xylem completely surrounds the phloem.
  • This type of bundle is also known as a leptocentric bundle.
  • It is typically found in the stems of some monocotyledonous plants such as Dracaena and Yucca.

Additional Information

  • Amphicribal
  • In this type, the phloem surrounds the xylem. It is also known as a hadrocentric bundle (e.g., Ferns).
  • Radial
  • In radial bundles, xylem and phloem are arranged on different radii, alternating with each other. This is a characteristic feature of roots.
  • Conjoint and Collateral
  • In this arrangement, xylem and phloem are present on the same radius.
  • In a collateral bundle, xylem is located towards the inner side and phloem is located towards the outer side. This is common in dicot stems.
  • Concentric Bundles
  • Amphivasal and Amphicribal are types of concentric bundles where one vascular tissue completely encircles the other.

Question 73

Cortical vascular bundles are found in the stem of

  1. AOption (a)

    Bignonia

  2. BOption (b)

    Mirabilis

  3. COption (c)

    Nyctanthes

  4. DOption (d)

    Chenopodium

View answer & explanation

Correct answer

Answer: (c)C.

Nyctanthes

Why this answer is correct

The correct answer is - Nyctanthes

Key Points

  • Nyctanthes
  • The stem of Nyctanthes (Night-flowering jasmine) is quadrangular (four-angled) in outline.
  • It is characterized by the presence of four cortical vascular bundles, which are situated in the four corners of the cortex.
  • These bundles are collateral and inversely oriented, meaning the xylem is directed towards the epidermis (periphery) and the phloem is directed towards the center.
  • This feature is considered an anatomical anomaly as vascular bundles are typically restricted to the stele in normal dicot stems.

Additional Information

  • Anomalous Primary Structures
  • Cortical Bundles: These are vascular bundles located in the cortex. Apart from Nyctanthes, they are also found in Casuarina and members of the family Melastomataceae.
  • Medullary Bundles: These are vascular bundles located in the pith (medulla). Examples include Mirabilis, Boerhavia, Amaranthus, and Bougainvillea.
  • Other Mentioned Plants
  • Bignonia: Shows anomalous secondary growth characterized by the formation of four wedges of secondary phloem that project into the secondary xylem.
  • Mirabilis: Shows the presence of medullary vascular bundles in the pith region.
  • Chenopodium: Exhibits anomalous secondary growth where concentric rings of vascular bundles are formed due to the activity of an extra-stelar cambium.
  • Significance
  • Such anatomical variations often provide mechanical strength or assist in efficient translocation of nutrients in plants with specific growth habits or environmental adaptations.

Question 74

Which of the following is not correctly matched?

  1. AOption (a)

    Syconus -Jack fruit

  2. BOption (b)

    Drupe -Date

  3. COption (c)

    Berry -Betel nut

  4. DOption (d)

    Nut -Cashew nut

View answer & explanation

Correct answer

Answer: (c)C.

Berry -Betel nut

Why this answer is correct

The correct answer is - Berry - Betel nut

Key Points

  • Berry - Betel nut
  • This pair is incorrectly matched because the Betel nut (Areca nut) is botanically classified as a Drupe, specifically a fibrous drupe.
  • In a Drupe, the fruit has a fleshy or fibrous middle layer (mesocarp) and a hard or stony inner layer (endocarp) surrounding the seed.
  • A Berry is a fleshy fruit in which the entire pericarp is soft and pulpy, such as in tomatoes or grapes.

Additional Information

  • Classification of Fruits
  • Syconus: This is a multiple fruit that develops from a hypanthodium inflorescence. Examples include Fig (Ficus), Banyan, and Gular. Jackfruit is actually a Sorosis (developed from a spike or spadix), making that pair incorrectly matched as well.
  • Drupe: A fleshy fruit with a stony endocarp. Examples include Mango, Coconut, and Betel nut. Date palm is often confused for a drupe but is botanically a single-seeded berry.
  • Nut: A dry, one-seeded fruit with a very hard, woody pericarp. The Cashew nut is a true nut that develops at the end of a fleshy pedicel known as the cashew apple. This is a correctly matched pair.
  • Note: In many standard botanical classifications for this specific question, Nut - Cashew nut is considered the only correctly matched pair, while Syconus - Jackfruit, Drupe - Date, and Berry - Betel nut are all technically mismatches.

Question 75

Integument is completely absent in ovule of

  1. AOption (a)

    Vanda

  2. BOption (b)

    Apium

  3. COption (c)

    Balanophora

  4. DOption (d)

    Physalis

View answer & explanation

Correct answer

Answer: (c)C.

Balanophora

Why this answer is correct

The correct answer is - Balanophora

Key Points

  • Ategmic Ovule
  • An ovule that completely lacks integuments is known as an ategmic ovule.
  • In Balanophora, which is a genus of parasitic plants, the ovules are ategmic, meaning no protective envelope (integument) surrounds the nucellus.
  • This condition is often found in some parasitic plant families where the ovule structure is significantly reduced.

Additional Information

  • Classification of Ovules based on Integuments
  • Unitegmic: Ovules having a single integument. This is commonly seen in members of Gamopetalae and Gymnosperms. Examples include Physalis and Apium.
  • Bitegmic: Ovules having two integuments. This is a common feature in most monocots (like Vanda) and polypetalous dicots.
  • Ategmic: Ovules without any integument. Examples include Balanophora, Santalum, and Loranthus.
  • Function of Integuments
  • Integuments are the protective envelopes of the ovule that eventually develop into the seed coat (testa and tegmen) after fertilization.
  • They surround the nucellus except at the small opening called the micropyle.
  • Vanda, Apium, and Physalis
  • Vanda (an orchid) typically possesses integuments (often bitegmic).
  • Apium (celery) and Physalis (groundcherry) belong to families that typically produce unitegmic ovules.

Question 76

Quicent centre occurs in

  1. AOption (a)

     Root cap

  2. BOption (b)

    Root apex

  3. COption (c)

    Shoot apex

  4. DOption (d)

    Leaves

View answer & explanation

Correct answer

Answer: (b)B.

Root apex

Why this answer is correct

The correct answer is - Root apex

Key Points

  • Quiescent Centre
  • The Quiescent Centre is a region located in the Root Apex (root apical meristem) where cell division proceeds very slowly or not at all.
  • It was first discovered by F.A.L. Clowes in 1956 in the roots of Zea mays (maize).
  • The cells in this region are characterized by low mitotic activity, low amounts of RNA, DNA, and proteins.
  • This center is positioned between the root cap and the active meristematic zone.

Additional Information

  • Function of Quiescent Centre
  • It acts as a reservoir of cells; if the surrounding actively dividing cells are damaged (e.g., by radiation or toxic chemicals), the quiescent cells become active and divide to restore the meristem.
  • It helps in the regeneration of the root tip and maintains the structural integrity of the root apical meristem.
  • Root Apex Structure
  • Root Cap: A protective layer at the tip of the root that protects the tender growing point as it pushes through the soil.
  • Meristematic Zone: The region where cells divide rapidly to facilitate root growth.
  • Quiescent Centre: Situated at the center of the root apex, acting as a stable core of cells.
  • Shoot Apex
  • The Shoot Apex is the growing tip of the shoot system. Unlike the root apex, it typically does not contain a defined quiescent centre identical to the one found in roots.
  • It is responsible for the formation of leaves and lateral buds.

Question 77

"Families of Flowering Plants" was written by

  1. AOption (a)

    Bentham and Hooker

  2. BOption (b)

    John Hutchinson

  3. COption (c)

    Takhtajan

  4. DOption (d)

    Bessey

View answer & explanation

Correct answer

Answer: (b)B.

John Hutchinson

Why this answer is correct

The correct answer is - John Hutchinson

Key Points

  • John Hutchinson
  • John Hutchinson was a famous British botanist associated with the Royal Botanic Gardens, Kew.
  • He authored the renowned book 'The Families of Flowering Plants', which was published in two volumes: Dicotyledons in 1926 and Monocotyledons in 1934.
  • His classification system is based on phylogenetic principles, aiming to reflect the evolutionary history of plants.

Additional Information

  • Bentham and Hooker
  • George Bentham and Joseph Dalton Hooker published the monumental work 'Genera Plantarum'.
  • Their classification system is considered a natural system and is widely used in herbaria across Britain and India.
  • Takhtajan
  • Armen Takhtajan was a Soviet-Armenian botanist who developed a comprehensive phylogenetic system of plant classification.
  • He wrote 'Flowering Plants: Origin and Dispersal' and 'Diversity and Classification of Flowering Plants'.
  • Bessey
  • Charles Bessey was an American botanist known for his phylogenetic system, often represented by the 'Besseyan Cactus'.
  • He published 'The Phylogenetic Taxonomy of Flowering Plants' in 1915, emphasizing that primitive flowers have many separate parts.
  • Hutchinson's Principles
  • Hutchinson's system is characterized by the separation of woody (Lignosae) and herbaceous (Herbaceae) families, a feature that was later criticized by some taxonomists but was foundational to his logic.

Question 78

'Monocarpellary' condition is found in

  1. AOption (a)

    Ranunculaceae

  2. BOption (b)

    Fabaceae

  3. COption (c)

    Liliaceae

  4. DOption (d)

    Fumariaceae

View answer & explanation

Correct answer

Answer: (b)B.

Fabaceae

Why this answer is correct

The correct answer is - Fabaceae

Key Points

  • Fabaceae
  • The Fabaceae family (formerly known as Papilionaceae) is characterized by a monocarpellary gynoecium.
  • In this condition, the gynoecium consists of a single carpel.
  • The ovary is superior, unilocular, and contains many ovules attached via marginal placentation.
  • Common examples of this family include pea (Pisum sativum), gram, and beans.

Additional Information

  • Gynoecium Variation
  • Ranunculaceae: Typically characterized by a multicarpellary and apocarpous gynoecium, where many carpels are present and remain free from each other.
  • Liliaceae: Characterized by a tricarpellary, syncarpous gynoecium with a superior ovary and axile placentation.
  • Fumariaceae: Usually possesses a bicarpellary, syncarpous gynoecium.
  • Terminology in Gynoecium
  • Monocarpellary: Gynoecium with one carpel.
  • Bicarpellary: Gynoecium with two carpels.
  • Tricarpellary: Gynoecium with three carpels.
  • Syncarpous: When carpels are fused together.
  • Apocarpous: When carpels are free from each other.

Question 79

Number of stamens found in oleaceae is

  1. AOption (a)

    5

  2. BOption (b)

    2

  3. COption (c)

    4

  4. DOption (d)

    3

View answer & explanation

Correct answer

Answer: (b)B.

2

Why this answer is correct

The correct answer is - 2

Key Points

  • Androecium in Oleaceae
  • In the family Oleaceae (Olive family), the number of stamens is typically 2.
  • These stamens are epipetalous, meaning they are attached to the corolla tube.
  • They are usually placed alternately with the corolla lobes or in a specific arrangement that characterizes the family.

Additional Information

  • Family Oleaceae
  • It is a family of flowering plants comprising about 26 genera and over 700 species.
  • Well-known members include Olea (olive), Jasminum (jasmine), Fraxinus (ash), and Syringa (lilac).
  • The plants are mostly shrubs or trees, sometimes climbers.
  • Floral Structure
  • Calyx: Usually 4 united sepals.
  • Corolla: Usually 4 united petals (gamopetalous), though they can be absent in some species like Ash.
  • Gynoecium: It is bicarpellary (2 carpels) and syncarpous with a superior ovary.
  • Floral Formula
  • The general floral formula for Oleaceae is represented as ⊕ ⚥ K(4) C(4) A2 G(2).
  • The A2 signifies the presence of two stamens.

Question 80

Nycanthes belongs to which family

  1. AOption (a)

    Ranunculaceae

  2. BOption (b)

    Oleaceae

  3. COption (c)

    Lythraceae

  4. DOption (d)

    None of the above

View answer & explanation

Correct answer

Answer: (b)B.

Oleaceae

Why this answer is correct

The correct answer is - Oleaceae

Key Points

  • Nyctanthes
  • The genus Nyctanthes belongs to the family Oleaceae.
  • It is primarily known for the species Nyctanthes arbor-tristis, commonly called the Night-flowering Jasmine, Parijat, or Harsingar.
  • The placement in Oleaceae is supported by morphological characteristics such as the presence of two stamens and the structure of the corolla.
  • Although it was historically sometimes associated with the family Verbenaceae, modern taxonomic studies and chemical evidence (like the presence of certain glycosides) place it firmly within Oleaceae.

Additional Information

  • Family Oleaceae
  • This family is often referred to as the Olive family.
  • Common features include opposite leaves, flowers with two stamens, and a superior ovary.
  • Important genera include Olea (Olive), Jasminum (Jasmine), and Fraxinus (Ash).
  • Ranunculaceae
  • Commonly known as the Buttercup family.
  • Members typically have numerous stamens and multiple free carpels (apocarpous gynoecium).
  • Lythraceae
  • Known as the Loosestrife family.
  • Flowers are characterized by the presence of a hypanthium (a floral tube) and petals that are often crumpled in the bud.
  • Nyctanthes arbor-tristis
  • It is a small tree or shrub with fragrant white flowers that have an orange-red center.
  • The flowers bloom at night and fall off the tree at dawn, giving it the name 'arbor-tristis' (sad tree).

Question 81

Fruit in which pericarp is fused with the seed coat is known as

  1. AOption (a)

    Berry

  2. BOption (b)

    Hespiridium

  3. COption (c)

    Caryopsis

  4. DOption (d)

    Capsule

View answer & explanation

Correct answer

Answer: (c)C.

Caryopsis

Why this answer is correct

The correct answer is - Caryopsis

Key Points

  • Caryopsis
  • A Caryopsis is a type of simple, dry, indehiscent fruit.
  • The defining characteristic of this fruit is that the pericarp (the fruit wall) is fused firmly with the seed coat (testa).
  • Because of this fusion, the fruit and the seed function as a single unit, often referred to as a grain.
  • This type of fruit is characteristic of the Poaceae (Gramineae) family, which includes most cereal crops.

Additional Information

  • Classification of Fruits
  • Berry: A fleshy fruit where the entire pericarp is soft and fleshy, typically containing multiple seeds (e.g., Tomato, Grapes). The seed coat is not fused with the pericarp.
  • Hesperidium: A specialized type of berry with a leathery rind (exocarp and mesocarp) and internal segments filled with juice-filled hairs (e.g., Orange, Lemon).
  • Capsule: A dry, dehiscent fruit that develops from a compound ovary and splits open at maturity to release seeds (e.g., Cotton, Datura).
  • Examples of Caryopsis
  • Common examples include Wheat, Maize, Rice, and Barley.
  • In these plants, what we commonly call the 'seed' is technically the entire fruit because the fruit wall is inseparable from the seed.

Question 82

Fruit of carrot is

  1. AOption (a)

    Siliqua

  2. BOption (b)

    Lomentum

  3. COption (c)

    Samara

  4. DOption (d)

    Cremocarp

View answer & explanation

Correct answer

Answer: (d)D.

Cremocarp

Why this answer is correct

The correct answer is - Cremocarp

Key Points

  • Cremocarp
  • The fruit of the carrot (Daucus carota) is a cremocarp.
  • A cremocarp is a type of schizocarpic fruit, which is a dry fruit that splits into single-seeded components at maturity.
  • It is the characteristic fruit of the Apiaceae (Umbelliferae) family, which includes plants like coriander, fennel, and cumin.
  • It develops from a bicarpellary, syncarpous, inferior ovary and eventually splits into two one-seeded units called mericarps.

Additional Information

  • Siliqua
  • This is a dry, dehiscent fruit that develops from a bicarpellary, superior ovary.
  • It is a characteristic feature of the Brassicaceae family (e.g., Mustard).
  • It dehisces from the base upward by two valves, leaving the seeds attached to a central false septum called the replum.
  • Lomentum
  • A lomentum is a modification of a legume fruit.
  • It is characterized by constrictions between the seeds, causing the fruit to break into one-seeded segments at maturity (e.g., Mimosa, Radish).
  • Samara
  • A samara is a dry, indehiscent, one-seeded fruit.
  • The pericarp is extended into a wing-like structure that facilitates dispersal by wind (e.g., Hiptage, Holoptelea).

Question 83

Tribulus terrestris (Gokharu) belongs to family

  1. AOption (a)

    Lythraceae

  2. BOption (b)

    Acanthaceae

  3. COption (c)

    Zygophyllaceae

  4. DOption (d)

    Cyperaceae

View answer & explanation

Correct answer

Answer: (c)C.

Zygophyllaceae

Why this answer is correct

The correct answer is - Zygophyllaceae

Key Points

  • Tribulus terrestris
  • Tribulus terrestris, commonly known as Gokharu or Puncture Vine, is a taprooted herbaceous perennial plant.
  • It belongs to the family Zygophyllaceae.
  • It is widely distributed around the world and is well-adapted to grow in dry climate locations where few other plants can survive.
  • In traditional medicine, especially Ayurveda, it is used for various purposes including urinary disorders and as an aphrodisiac.

Additional Information

  • Zygophyllaceae Family
  • Known as the Caltrop family or Bean-caper family.
  • Plants in this family are typically herbs, shrubs, or trees found in desert or saline habitats.
  • The leaves are usually opposite and stipulate.
  • The fruit is often a schizocarp or a capsule.
  • Other Families Mentioned
  • Lythraceae: Known as the Loosestrife family. Examples include Lawsonia inermis (Henna) and Punica granatum (Pomegranate).
  • Acanthaceae: Known as the Acanthus family. Examples include Adhatoda vasica (Vasa) and Andrographis paniculata (Kalmegh).
  • Cyperaceae: Known as the Sedge family. These are monocotyledonous graminoid (grass-like) flowering plants. An example is Cyperus rotundus (Nagarmotha).

Question 84

Ligulate leaf and versatile anther is found in

  1. AOption (a)

    Ranunculaceae

  2. BOption (b)

    Poaceae

  3. COption (c)

    Rutaceae

  4. DOption (d)

    Malvaceae

View answer & explanation

Correct answer

Answer: (b)B.

Poaceae

Why this answer is correct

The correct answer is - Poaceae

Key Points

  • Poaceae (Gramineae)
  • Ligulate Leaf: In members of the Poaceae family, a ligule is a characteristic membranous outgrowth or a fringe of hairs located at the junction of the leaf blade and the leaf sheath.
  • Versatile Anther: The anthers in this family are versatile, meaning the filament is attached to the back of the anther at a single point, allowing the anther to swing freely in the wind.
  • This combination of features is highly specialized for anemophily (wind pollination), as the free-moving anthers easily disperse pollen into the air.

Additional Information

  • Family Poaceae
  • Commonly known as the grass family, it includes essential crops like wheat, rice, and maize.
  • The inflorescence is typically a spikelet, and the fruit is a caryopsis (where the seed coat is fused with the fruit wall).
  • Comparison with Other Families
  • Ranunculaceae: Usually possesses numerous stamens that are spirally arranged with adnate or basifixed anthers.
  • Rutaceae: Known for having a disk below the ovary and basifixed or dorsifixed anthers, often with oil glands on the plant body.
  • Malvaceae: Characterized by monadelphous stamens (filaments fused into a tube) and monothecous (one-lobed) reniform anthers.
  • Significance of Versatile Anthers
  • Versatile anthers are a key evolutionary adaptation for plants that do not rely on insects for pollination, ensuring maximum pollen exposure to air currents.

Question 85

Which of the following plants belongs to family Lythraceae ?

  1. AOption (a)

    Trapa bispinosa

  2. BOption (b)

    Seseli indicum

  3. COption (c)

    Lawsonia inermis

  4. DOption (d)

    Alstonia scholaris

View answer & explanation

Correct answer

Answer: (c)C.

Lawsonia inermis

Why this answer is correct

The correct answer is - Lawsonia inermis

Key Points

  • Lawsonia inermis
  • Lawsonia inermis, commonly known as Henna or Mehandi, is a primary member of the Lythraceae family.
  • The family Lythraceae is also known as the loosestrife family, which includes trees, shrubs, and some herbaceous plants.
  • Plants in this family typically have opposite or whorled leaves and flowers with crumpled petals in the bud stage.
  • Henna is widely known for the dye produced from its leaves, which is used for body art and hair coloring.

Additional Information

  • Trapa bispinosa
  • Commonly known as Water Chestnut (Singhara).
  • While modern botanical systems (like APG) sometimes merge it into Lythraceae, it is traditionally classified under its own family, Trapaceae.
  • Seseli indicum
  • It belongs to the family Apiaceae (formerly known as Umbelliferae).
  • This family is characterized by plants having umbel inflorescences, such as coriander, cumin, and carrots.
  • Alstonia scholaris
  • Commonly known as the Scholar Tree, Blackboard tree, or Devil's tree.
  • It belongs to the family Apocynaceae (the Dogbane family), known for producing milky latex.

Question 86

In malvaceae, the aestivation of corolla is

  1. AOption (a)

    Twisted

  2. BOption (b)

    Valvate

  3. COption (c)

    Quincuncial

  4. DOption (d)

    Ascending imbricate

View answer & explanation

Correct answer

Answer: (a)A.

Twisted

Why this answer is correct

The correct answer is - Twisted

Key Points

  • Twisted Aestivation
  • In the family Malvaceae (which includes plants like Hibiscus, Cotton, and Okra), the corolla (petals) typically exhibits twisted aestivation.
  • Twisted aestivation is defined as a condition where one margin of a petal overlaps that of the next member, and the other margin is overlapped by the preceding one.
  • This results in a directional, overlapping spiral arrangement of the petals in the bud stage.

Additional Information

  • Types of Aestivation
  • Valvate: The margins of sepals or petals touch each other without any overlapping (e.g., Calotropis).
  • Imbricate: The margins overlap one another but not in any specific or regular direction (e.g., Cassia and Gulmohar).
  • Vexillary: Also known as papilionaceous aestivation, found in Fabaceae. It consists of five petals: a large standard, two wings, and two fused keels.
  • Quincuncial: A type of imbricate aestivation where two petals are external, two are internal, and one is half-internal and half-external.
  • Characteristics of Malvaceae
  • The flowers are generally actinomorphic and hypogynous.
  • A distinguishing feature is the monadelphous stamens, where filaments are fused to form a staminal tube around the style.
  • The anthers are monothecous (single-lobed) and reniform (kidney-shaped).

Question 87

Butea monosperma belongs to family

  1. AOption (a)

    Brassicaceae

  2. BOption (b)

    Solanaceae

  3. COption (c)

    Fabaceae

  4. DOption (d)

    Oleaceae

View answer & explanation

Correct answer

Answer: (c)C.

Fabaceae

Why this answer is correct

The correct answer is - Fabaceae

Key Points

  • Butea monosperma is a flowering plant commonly known as the "Flame of the Forest" or "Palash."
  • It belongs to the family Fabaceae, which is also known as the legume or bean family.
  • The Fabaceae family is characterized by:
  • Compound leaves, which are often pinnate or trifoliate.
  • Presence of papilionaceous flowers with five petals arranged as a standard, wings, and keel.
  • Production of leguminous fruits (pods).
  • Butea monosperma is native to tropical and subtropical regions of the Indian subcontinent.

Additional Information

  • Fabaceae Family
  • One of the largest plant families, with over 19,000 species globally.
  • Includes economically important plants such as soybeans, peas, lentils, and alfalfa.
  • Many members of this family are capable of nitrogen fixation through symbiotic relationships with rhizobium bacteria in root nodules.
  • Butea monosperma Uses
  • The flowers of Butea monosperma are used to produce natural dyes.
  • It has applications in traditional medicine for treating conditions such as skin disorders and infections.
  • The tree is also valued for its timber and as a source of fodder for livestock.
  • Other Families (Incorrect Options)
  • Brassicaceae: Includes plants like mustard and cabbage, known for their cruciform flowers.
  • Solanaceae: Known as the nightshade family, includes plants like tomatoes, potatoes, and bell peppers.
  • Oleaceae: Includes plants like olive and jasmine, known for their simple leaves and fragrant flowers.

Question 88

In Malvaceae, epicalyx is absent in

  1. AOption (a)

    Hibiscus

  2. BOption (b)

    Malva

  3. COption (c)

    Sida

  4. DOption (d)

    Malvastrum

View answer & explanation

Correct answer

Answer: (c)C.

Sida

Why this answer is correct

The correct answer is - Sida

Key Points

  • Sida
  • The genus Sida is a member of the Malvaceae family.
  • A defining taxonomic feature of the genus Sida is the absence of an epicalyx.
  • While the majority of genera in the Malvaceae family possess an epicalyx (a whorl of bracteoles outside the calyx), Sida and Abutilon are the primary exceptions where it is absent.

Additional Information

  • Family Malvaceae
  • Commonly known as the Mallow family, it includes plants like cotton, okra, and hibiscus.
  • Epicalyx: It is an additional whorl of leaf-like structures found outside the calyx. It is present in Hibiscus, Malva, and Malvastrum.
  • Staminal Tube: A characteristic feature where filaments of stamens fuse to form a tube (monadelphous condition) surrounding the style.
  • Anthers: They are typically monothecous (one-lobed) and reniform (kidney-shaped) with transverse dehiscence.
  • Comparison of Genera
  • Hibiscus: Usually possesses an epicalyx consisting of 5 to many bracteoles.
  • Malva: Generally has an epicalyx composed of 3 bracteoles.
  • Malvastrum: Characterized by the presence of an epicalyx, typically with 3 small bracteoles.
  • Sida and Abutilon: These are the notable genera within the family where the epicalyx is missing.

Question 89

In Pinus, the germination of seed is

  1. AOption (a)

    Viviparous

  2. BOption (b)

    Hypogeal

  3. COption (c)

    Epigeal

  4. DOption (d)

    None of the above

View answer & explanation

Correct answer

Answer: (c)C.

Epigeal

Why this answer is correct

The correct answer is - Epigeal

Key Points

  • Epigeal Germination
  • In Pinus, seed germination is epigeal, meaning the cotyledons are pushed above the soil surface.
  • This occurs because the hypocotyl (the part of the axis below the cotyledons) elongates rapidly and curves to pull the cotyledons out of the ground.
  • Once they reach the surface, the seed coat is shed, and the cotyledonary leaves expand and turn green to begin photosynthesis.

Additional Information

  • Types of Seed Germination
  • Epigeal Germination: Found in plants like Pinus, castor, and beans. The hypocotyl elongates, bringing cotyledons above ground.
  • Hypogeal Germination: Found in plants like pea, gram, and maize. The epicotyl elongates, and the cotyledons remain underground.
  • Vivipary: A special type of germination where the seed germinates while still attached to the parent plant, common in mangrove plants like Rhizophora.
  • Characteristics of Pinus
  • Pinus is a Gymnosperm with seeds that are often winged for wind dispersal.
  • The embryo of Pinus is polycotyledonous, containing a whorl of many cotyledons.
  • The germination process requires favorable conditions of moisture, temperature, and oxygen.

Question 90

If the root of Pinus has 64 chromosomes, what would be the number of chromosomes in its endosperm?

  1. AOption (a)

    64

  2. BOption (b)

    32

  3. COption (c)

    96

  4. DOption (d)

    16

View answer & explanation

Correct answer

Answer: (b)B.

32

Why this answer is correct

The correct answer is - 32

Key Points

  • Ploidy of Pinus Root
  • Pinus is a gymnosperm, and the main plant body (including roots, stems, and leaves) is sporophytic.
  • The sporophyte is diploid (2n). Therefore, if the root has 64 chromosomes, 2n = 64.
  • Ploidy of Pinus Endosperm
  • In gymnosperms like Pinus, the endosperm represents the female gametophyte.
  • It is formed before fertilization from the functional megaspore through repeated mitotic divisions.
  • Since it is a gametophytic tissue, its ploidy is haploid (n).
  • Calculation
  • If 2n = 64, then n = 64 / 2 = 32.
  • Thus, the number of chromosomes in the endosperm of Pinus is 32.

Additional Information

  • Endosperm in Gymnosperms vs. Angiosperms
  • Gymnosperms: The endosperm is haploid (n) because it develops directly from the megaspore before fertilization.
  • Angiosperms: The endosperm is typically triploid (3n) because it is formed as a result of triple fusion (one male gamete fusing with two polar nuclei) during double fertilization.
  • Chromosome Sets
  • Haploid (n): A single set of chromosomes found in gametes and gametophytic tissues.
  • Diploid (2n): Two sets of chromosomes found in zygotes and sporophytic tissues (roots, leaves, etc.).
  • Triploid (3n): Three sets of chromosomes, common in the endosperm of flowering plants.

Question 91

Angiosperms were divided into magnoliopsida and liliopsida in which system of classification?

  1. AOption (a)

    Cronquist

  2. BOption (b)

    Takhtajan

  3. COption (c)

    Bessey

  4. DOption (d)

    Hutchinson

View answer & explanation

Correct answer

Answer: (a)A.

Cronquist

Why this answer is correct

The correct answer is - Cronquist

Key Points

  • Cronquist System
  • Arthur Cronquist (1981) proposed a widely used phylogenetic system of classification in his work An Integrated System of Classification of Flowering Plants.
  • He divided the division Magnoliophyta (Angiosperms) into two broad classes: Magnoliopsida (Dicotyledons) and Liliopsida (Monocotyledons).
  • This classification is based on a wide range of characters including morphology, anatomy, embryology, and phytochemistry.

Additional Information

  • Classification Details
  • Magnoliopsida (Dicots): This class is further divided into 6 subclasses, 64 orders, and 318 families. The subclasses include Magnoliidae, Hamamelidae, Caryophyllidae, Dilleniidae, Rosidae, and Asteridae.
  • Liliopsida (Monocots): This class is divided into 5 subclasses, 19 orders, and 65 families. The subclasses include Alismatidae, Arecidae, Commelinidae, Zingiberidae, and Liliidae.
  • Other Systems
  • Takhtajan: Armen Takhtajan also developed a phylogenetic system where he used the names Magnoliopsida and Liliopsida, but his arrangement and subdivision of these classes differ from Cronquist.
  • Hutchinson: John Hutchinson proposed a system based on habit, dividing plants into Lignosae (woody) and Herbaceae (herbaceous).
  • Bessey: Charles Bessey is known for Bessey's Cactus, a phylogenetic arrangement where he considered the Ranales as the most primitive group.

Question 92

Select a pair of plants which are vesselless.

  1. AOption (a)

    Cycas and Drimys

  2. BOption (b)

    Gnetum and Trapa

  3. COption (c)

    Pinus and Vanda

  4. DOption (d)

    Drimys and Vanda

View answer & explanation

Correct answer

Answer: (a)A.

Cycas and Drimys

Why this answer is correct

The correct answer is - Cycas and Drimys

Key Points

  • Vesselless plants
  • Vesselless plants lack vessels, which are specialized structures for water conduction found in angiosperms.
  • Cycas and Drimys are examples of plants that do not have vascular vessels and rely on tracheids for water conduction.
  • Cycas
  • Cycas is a gymnosperm and lacks vessels in its xylem tissue.
  • It relies entirely on tracheids for water transport and structural support.
  • Drimys
  • Drimys, belonging to the family Winteraceae, is a primitive angiosperm.
  • It lacks vessels and instead utilizes tracheids for conducting water, making it similar to gymnosperms in terms of vascular structure.

Additional Information

  • Tracheids vs Vessels
  • Tracheids are elongated cells in the xylem that conduct water and provide structural support.
  • Vessels are more specialized, tube-like structures found in angiosperms, allowing efficient water conduction.
  • Gymnosperms like Cycas and primitive angiosperms like Drimys lack vessels and rely solely on tracheids.
  • Plant Groups
  • Gymnosperms: Non-flowering plants with vascular systems that lack vessels (e.g., Cycas).
  • Primitive Angiosperms: Early-evolving flowering plants, some of which lack vessels (e.g., Drimys).
  • Incorrect Options
  • Gnetum and Trapa: Gnetum is a gymnosperm but has vessels, and Trapa is an angiosperm with vessels.
  • Pinus and Vanda: Pinus is a gymnosperm and lacks vessels, but Vanda is an advanced angiosperm with vessels.
  • Drimys and Vanda: Drimys lacks vessels, but Vanda has a vascular system with vessels.

Question 93

'White rust disease of crucifers iscaused by

  1. AOption (a)

    Albugo candida

  2. BOption (b)

    Puccinia recondita

  3. COption (c)

    Xanthomonas campestris

  4. DOption (d)

    None of the above

View answer & explanation

Correct answer

Answer: (a)A.

Albugo candida

Why this answer is correct

The correct answer is - Albugo candida

Key Points

  • Albugo candida
  • Albugo candida is an obligate plant pathogen that causes the White rust (or white blister) disease in various cruciferous plants.
  • It primarily affects members of the Brassicaceae family, including mustard, cabbage, cauliflower, radish, and turnip.
  • The disease is characterized by the appearance of white, shiny, blister-like pustules (sori) on the lower surface of leaves, stems, and floral parts.
  • These pustules contain sporangia, which are dispersed by wind or water to spread the infection.

Additional Information

  • Puccinia recondita
  • This is a fungal pathogen responsible for Brown rust or Leaf rust in wheat.
  • It produces reddish-brown uredinia on the leaf blades, which can significantly reduce crop yield.
  • Xanthomonas campestris
  • This is a bacterium that causes several plant diseases, most notably Black rot in crucifers.
  • Symptoms include V-shaped yellow lesions starting from leaf margins and darkening of the vascular tissues.
  • Nature of White Rust
  • Although called 'rust', Albugo is not a true rust fungus (which belongs to Basidiomycota); it belongs to the class Oomycetes (water molds).
  • The disease causes hypertrophy (increase in cell size) and hyperplasia (increase in cell number), leading to deformities in the host plant organs.

Question 94

Cauliflower mosaic virus has

  1. AOption (a)

    Both R.N.A. and D.N.A.

  2. BOption (b)

     Single stranded R.N.A.

  3. COption (c)

    Double stranded R.N.A.

  4. DOption (d)

     Double stranded D.N.A.

View answer & explanation

Correct answer

Answer: (d)D.

 Double stranded D.N.A.

Why this answer is correct

The correct answer is - Double stranded D.N.A.

Key Points

  • Double stranded D.N.A.
  • Cauliflower Mosaic Virus (CaMV) is a member of the Caulimovirus genus and belongs to the Caulimoviridae family.
  • The genetic material of CaMV consists of a circular double-stranded D.N.A. (dsDNA) genome.
  • It is known as a pararetrovirus because it replicates its D.N.A. genome through an R.N.A. intermediate using the enzyme reverse transcriptase.
  • The genome is approximately 8.0 kilobase pairs (kb) in size and contains several open reading frames (ORFs) that encode proteins for replication and movement.

Additional Information

  • Virus Classification by Genetic Material
  • Viruses are classified based on the type of nucleic acid they carry:
  • Single-stranded R.N.A. (ssRNA): Examples include Tobacco Mosaic Virus (TMV), Influenza virus, and HIV.
  • Double-stranded R.N.A. (dsRNA): Examples include Reoviruses and Rotaviruses.
  • Single-stranded D.N.A. (ssDNA): Examples include Bacteriophage φX174 and Parvoviruses.
  • Double-stranded D.N.A. (dsDNA): Examples include T-even bacteriophages, Adenoviruses, and Cauliflower Mosaic Virus.
  • Host Range and Transmission
  • CaMV primarily infects plants in the Brassicaceae family, such as cauliflower, broccoli, and cabbage.
  • It is transmitted from plant to plant by aphids in a non-circulative, non-persistent manner.
  • The virus causes symptoms like vein clearing, mosaic patterns, and stunting in affected plants.

Question 95

Which of the following fungi has acellular protoplasmic body and moves by pseudopodia?

  1. AOption (a)

    Physarum

  2. BOption (b)

    Plasmodiophora

  3. COption (c)

    Saccharomyces

  4. DOption (d)

    Synchytrium

View answer & explanation

Correct answer

Answer: (a)A.

Physarum

Why this answer is correct

The correct answer is - Physarum

Key Points

  • Physarum
  • Physarum is a type of slime mold, belonging to the Myxomycetes group.
  • It has an acellular protoplasmic body, which means it exists as a continuous mass of protoplasm without cellular boundaries.
  • Physarum moves by extending pseudopodia, which are temporary projections of its protoplasm.
  • This movement is facilitated by cytoplasmic streaming, allowing the organism to search for food and nutrients.

Additional Information

  • Slime molds
  • Slime molds are neither true fungi nor true protists but are classified as fungus-like organisms.
  • They exhibit characteristics of both fungi and protozoa during their lifecycle.
  • Examples include Physarum and Dictyostelium.
  • Pseudopodia
  • Pseudopodia are extensions of the cell membrane and cytoplasm used for locomotion and feeding.
  • They are characteristic of certain protists like amoebas and also found in slime molds like Physarum.
  • Protoplasmic streaming
  • Protoplasmic streaming is a phenomenon where the cytoplasm flows within the cell, aiding in the transport of nutrients and movement.
  • It is crucial for organisms like Physarum to facilitate pseudopodia formation and movement.

Question 96

Antheridia and Archegonia in ferns are produced on

  1. AOption (a)

    mature sporophyte

  2. BOption (b)

    young sporophyte

  3. COption (c)

     prothallus

  4. DOption (d)

    None of the above

View answer & explanation

Correct answer

Answer: (c)C.

 prothallus

Why this answer is correct

The correct answer is - Prothallus

Key Points

  • Antheridia and Archegonia are the male and female reproductive structures, respectively, in ferns.
  • These structures are produced on the prothallus, which is the gametophyte stage in the life cycle of ferns.
  • The prothallus is typically a small, heart-shaped, and photosynthetic structure that grows independently of the sporophyte.
  • Ferns exhibit an alternation of generations, where the gametophyte stage (prothallus) gives rise to reproductive organs, leading to the formation of the next sporophyte generation.

Additional Information

  • Prothallus
  • It is a haploid structure that arises from the germination of a fern spore.
  • The prothallus contains rhizoids, which anchor it to the soil and assist in water absorption.
  • Life Cycle of Ferns
  • Ferns have a diplohaplontic life cycle, alternating between a diploid sporophyte and a haploid gametophyte.
  • The sporophyte is the dominant, photosynthetic phase, while the gametophyte is a temporary, independent phase.
  • Reproductive Structures
  • Antheridia produce motile male gametes (sperm), while Archegonia produce a single egg cell.
  • Fertilization occurs in the presence of water, allowing the sperm to swim to the egg in the archegonium.

Question 97

'Horse tail' is the common name of

  1. AOption (a)

    Selaginella

  2. BOption (b)

    Lycopodium

  3. COption (c)

    Equisetum

  4. DOption (d)

    Dryopteris

View answer & explanation

Correct answer

Answer: (c)C.

Equisetum

Why this answer is correct

The correct answer is - Equisetum

Key Points

  • Equisetum
  • Equisetum is the only living genus in the family Equisetaceae and is commonly known as Horsetail.
  • The name is derived from the Latin words equus (horse) and seta (bristle), referring to the plant's appearance.
  • These plants are characterized by jointed stems, whorled leaves, and the presence of silica in their cell walls, giving them a gritty texture.

Additional Information

  • Classification of Pteridophytes
  • Pteridophytes are classified into four main classes: Psilopsida, Lycopsida, Sphenopsida, and Pteropsida.
  • Selaginella: Commonly known as Spike moss or Little club moss; it belongs to the class Lycopsida.
  • Lycopodium: Commonly known as Club moss; it also belongs to the class Lycopsida.
  • Equisetum: Belongs to the class Sphenopsida.
  • Dryopteris: Commonly known as Wood fern or Male shield fern; it belongs to the class Pteropsida.
  • Economic Importance
  • Some species of Equisetum are used as scouring rushes due to the high silica content, which makes them useful for cleaning metal pots.
  • Pteridophytes like Dryopteris are often grown as ornamental plants.

Question 98

Neuromotor apparatus is found in

  1. AOption (a)

    Pogonatum

  2. BOption (b)

    Batrachospermum

  3. COption (c)

    Chlamydomonas

  4. DOption (d)

    Scytonema

View answer & explanation

Correct answer

Answer: (c)C.

Chlamydomonas

Why this answer is correct

The correct answer is - Chlamydomonas

Key Points

  • Neuromotor Apparatus
  • In Chlamydomonas, the movement of flagella is coordinated by a complex system known as the neuromotor apparatus.
  • This apparatus consists of several parts: the blepharoplasts (basal granules from which flagella arise), the paradesmos (connecting the two blepharoplasts), and the rhizoplast (a fiber connecting the blepharoplast to the centrosome or nucleus).
  • Its primary function is to coordinate the beating of the flagella, allowing the organism to move efficiently toward light or nutrients.

Additional Information

  • Chlamydomonas
  • It is a genus of unicellular green algae (Chlorophyta) found in stagnant water and on damp soil.
  • It possesses a cup-shaped chloroplast, a red eyespot (stigma) for light detection, and two equal flagella.
  • Pogonatum
  • It is a genus of mosses (Bryophyta). While its sperm cells are flagellated, the term neuromotor apparatus is specifically used for the coordination system in flagellated algae like Chlamydomonas.
  • Batrachospermum
  • It is a freshwater red alga (Rhodophyta). A defining characteristic of red algae is the total absence of flagellated stages in their life cycle.
  • Scytonema
  • It is a genus of cyanobacteria (blue-green algae). As prokaryotes, they do not have eukaryotic flagella or a neuromotor apparatus; they are typically non-motile or move by gliding.

Question 99

In Escherichia coli, the lac operon is induced by

  1. AOption (a)

    Lactose

  2. BOption (b)

    Promoter gene

  3. COption (c)

    ẞ-galactosidase

  4. DOption (d)

    Operator gene

View answer & explanation

Correct answer

Answer: (a)A.

Lactose

Why this answer is correct

The correct answer is - Lactose

Key Points

  • Lactose (The Inducer)
  • In the lac operon of Escherichia coli, Lactose (or more specifically its isomer, allolactose) acts as the inducer.
  • When lactose is present in the medium, it enters the cell and binds to the repressor protein produced by the regulatory gene (i gene).
  • This binding inactivates the repressor, preventing it from binding to the operator region. As a result, RNA polymerase can move past the operator and transcribe the structural genes.

Additional Information

  • Components of Lac Operon
  • Structural Genes: There are three structural genes:
  • lacZ: Codes for ẞ-galactosidase, which hydrolyzes lactose into glucose and galactose.
  • lacY: Codes for Permease, which increases the permeability of the cell to ẞ-galactosides.
  • lacA: Codes for Transacetylase.
  • Regulatory Gene (i gene): It codes for the repressor protein that continuously suppresses the operon in the absence of an inducer.
  • Promoter (P): The site where RNA polymerase binds to initiate transcription.
  • Operator (O): The segment of DNA where the repressor protein binds to stop transcription.
  • Mechanism of Regulation
  • The lac operon is a classic example of negative inducible regulation.
  • In the absence of lactose, the repressor binds to the operator, switching OFF the operon.
  • In the presence of lactose, the inducer-repressor complex is formed, freeing the operator and switching ON the operon for the synthesis of enzymes required for lactose metabolism.

Question 100

Floridean starch is found in

  1. AOption (a)

    Chlorophyceae

  2. BOption (b)

    Rhodophyceae

  3. COption (c)

    Cyanophyceae

  4. DOption (d)

    Bacillariophyceae

View answer & explanation

Correct answer

Answer: (a)A.

Chlorophyceae

Why this answer is correct

Code

**The correct answer is - Rhodophyceae**

 Key Points

- **Floridean starch**
- It is the primary **storage polysaccharide** found in members of the **Rhodophyceae**, which is a class of red algae.
- Floridean starch is stored in the form of granules in the **cytoplasm** of red algae cells, and it serves as an energy reserve.
- This polysaccharide is structurally similar to glycogen and is distinct from the starch found in green plants and other algae.
- **Rhodophyceae**
- This class of algae is characterized by the presence of the pigments **phycoerythrin** and **phycocyanin**, which give them their red coloration.
- They are predominantly found in marine environments, especially in warm, tropical waters.

 Additional Information

- **Comparison with other algal classes**
- **Chlorophyceae**: Members of this class store their energy reserves in the form of true starch, which is similar to the starch found in higher plants.
- **Cyanophyceae**: Also known as blue-green algae, they store energy as **cyanophycean starch**, which is structurally different from floridean starch.
- **Bacillariophyceae**: Commonly known as diatoms, they store their energy reserves as **chrysolaminarin**, a polysaccharide distinct from floridean starch.
- **Role of storage polysaccharides**
- Storage polysaccharides like floridean starch provide energy to algae during unfavorable conditions such as low light or nutrient depletion.
- These compounds are also crucial for survival and reproduction in various aquatic ecosystems.

Question 101

A moss differs from a fern in having

  1. AOption (a)

    Alternation of generation

  2. BOption (b)

    A dependent sporophyte

  3. COption (c)

    An independent gametophyte

  4. DOption (d)

    Swimming sperms

View answer & explanation

Correct answer

Answer: (b)B.

A dependent sporophyte

Why this answer is correct

The correct answer is - A dependent sporophyte

Key Points

  • Dependent Sporophyte
  • In mosses (Bryophytes), the sporophyte is physically attached to and nutritionally dependent on the gametophyte throughout its life.
  • In ferns (Pteridophytes), the sporophyte is the dominant phase and is independent of the gametophyte once it matures.
  • The moss sporophyte consists of a foot, seta, and capsule, and it relies on the green gametophyte for water and nutrients.

Additional Information

  • Alternation of Generation
  • Both mosses and ferns exhibit alternation of generations, where a haploid gametophyte phase alternates with a diploid sporophyte phase.
  • Independent Gametophyte
  • In both mosses and ferns, the gametophyte is free-living and independent. In ferns, this small heart-shaped gametophyte is called a prothallus.
  • Swimming Sperms
  • Both groups require water for fertilization. They produce flagellated male gametes (antherozoids) that must swim through a film of water to reach the egg in the archegonium.
  • Dominant Phase
  • In mosses, the gametophyte is the dominant, photosynthetic, and more conspicuous stage of the life cycle.
  • In ferns, the sporophyte is the dominant, larger, and vascular stage of the life cycle.

Question 102

Which one of the following disease is caused by Claviceps purpurea ?

  1. AOption (a)

    Ergot of rye

  2. BOption (b)

    Early blight of potato

  3. COption (c)

    Rust of linseed

  4. DOption (d)

     Blast of rice

View answer & explanation

Correct answer

Answer: (a)A.

Ergot of rye

Why this answer is correct

The correct answer is - Ergot of rye

Key Points

  • Ergot of rye
  • This disease is caused by the fungus Claviceps purpurea, which belongs to the class Ascomycetes.
  • The fungus infects the ovaries of rye and other cereal plants, replacing the grain with a hard, dark-colored fungal structure known as a sclerotium (or ergot).
  • The sclerotia contain toxic alkaloids such as ergotamine, which can cause serious poisoning in humans and animals if consumed.

Additional Information

  • Early blight of potato
  • It is caused by the fungus Alternaria solani.
  • It is characterized by the appearance of small, dark, concentric spots on the leaves, often called target spots.
  • Rust of linseed
  • It is caused by the fungus Melampsora lini.
  • This disease affects all above-ground parts of the flax/linseed plant, producing bright orange-colored pustules.
  • Blast of rice
  • It is caused by the fungus Magnaporthe oryzae (also known as Pyricularia oryzae).
  • It is one of the most destructive diseases of rice worldwide, causing lesions on leaves, nodes, and panicles.
  • Ergotism
  • Consuming grains contaminated with ergot leads to a condition called Ergotism, historically known as St. Anthony's Fire.
  • Symptoms include gangrene (due to constriction of blood vessels) and hallucinations.

Question 103

Example of parasitic algae is

  1. AOption (a)

    Cephaleuros

  2. BOption (b)

    Polysiphonia

  3. COption (c)

    Batrachospermum

  4. DOption (d)

    None of the above

View answer & explanation

Correct answer

Answer: (a)A.

Cephaleuros

Why this answer is correct

The correct answer is - Cephaleuros

Key Points

  • Cephaleuros
  • Cephaleuros is a genus of parasitic thalloid green algae.
  • It is a notable exception in the world of algae, as most algae are free-living and autotrophic.
  • The most common species, Cephaleuros virescens, causes a disease known as Red Rust of tea and coffee.
  • The parasite lives sub-epidermally (under the cuticle) of the leaves and sometimes stems of the host plant, affecting the plant's health and productivity.

Additional Information

  • Batrachospermum
  • It is a genus of freshwater red algae.
  • It is commonly referred to as frog-spawn algae due to its beaded and gelatinous appearance.
  • It is free-living and typically found in clean, cool, running water.
  • Polysiphonia
  • It is a genus of marine red algae (Rhodophyceae).
  • It is characterized by its filamentous and highly branched thallus.
  • It is free-living and widely distributed in coastal marine environments.
  • Red Rust of Tea
  • This disease is specifically caused by Cephaleuros and can cause significant economic losses in tea plantations by reducing the photosynthetic area and causing premature leaf fall.

Question 104

During transcription RNA polymerase binds to

  1. AOption (a)

    Structural gene

  2. BOption (b)

    Promoter gene

  3. COption (c)

    Regulator gene

  4. DOption (d)

    Operator gene

View answer & explanation

Correct answer

Answer: (b)B.

Promoter gene

Why this answer is correct

The correct answer is - Promoter gene

Key Points

  • Promoter Gene
  • The promoter is a specific DNA sequence that provides the binding site for the enzyme RNA polymerase.
  • It is located at the 5' end (upstream) of the structural gene in a transcription unit.
  • The binding of RNA polymerase to the promoter is the initiation step of transcription, determining where the process begins and which DNA strand serves as the template.

Additional Information

  • Transcription Unit
  • A transcription unit in DNA is primarily defined by three regions: the Promoter, the Structural gene, and the Terminator.
  • Structural Gene: This is the portion of DNA that is actually transcribed into an RNA molecule.
  • Terminator: Located at the 3' end of the coding strand, it defines the end of the transcription process.
  • Regulatory Elements (in Operons)
  • Operator Gene: A segment of DNA where a repressor protein binds. It acts as a switch; when the repressor is bound, RNA polymerase is physically blocked from transcribing the genes.
  • Regulator Gene: This gene codes for a repressor protein (or activator) that controls the expression of the structural genes by interacting with the operator.
  • RNA Polymerase Function
  • In prokaryotes, a single RNA polymerase catalyzes the transcription of all types of RNA (mRNA, tRNA, rRNA).
  • In eukaryotes, there are different types: RNA polymerase I (rRNAs), RNA polymerase II (mRNA precursors), and RNA polymerase III (tRNA and small RNAs).

Question 105

Which of the following is produced in cyclic photo-phosphorylation?

  1. AOption (a)

     NADPH + H+

  2. BOption (b)

    ATP

  3. COption (c)

    Oxygen

  4. DOption (d)

    None of the above

View answer & explanation

Correct answer

Answer: (b)B.

ATP

Why this answer is correct

The correct answer is - ATP

Key Points

  • ATP is produced during cyclic photophosphorylation.
  • In cyclic photophosphorylation, only Photosystem I (PSI) is involved.
  • The process does not produce NADPH or oxygen.
  • Instead, electrons are cycled back to Photosystem I, enabling ATP production through the electron transport chain.
  • This process is essential for meeting the energy demands of the cell when ATP is required more than NADPH.

Additional Information

  • Photophosphorylation
  • Refers to the process of ATP synthesis in chloroplasts during photosynthesis.
  • Occurs in two forms: cyclic and non-cyclic.
  • Cyclic Photophosphorylation
  • Involves only Photosystem I.
  • Electrons follow a cyclic path, returning to Photosystem I after traveling through the electron transport chain.
  • Does not produce NADPH or oxygen, as water is not split.
  • Non-Cyclic Photophosphorylation
  • Involves both Photosystem I and Photosystem II.
  • Electrons do not return to their original photosystem.
  • Results in the production of ATP, NADPH, and oxygen (via water splitting).

Question 106

To which of the following classes of enzymes, the enzyme dehydrogenase will be placed ?

  1. AOption (a)

    Oxidoreductases

  2. BOption (b)

    Transferases

  3. COption (c)

    Hydrolases

  4. DOption (d)

    Lyases

View answer & explanation

Correct answer

Answer: (a)A.

Oxidoreductases

Why this answer is correct

The correct answer is - Oxidoreductases

Key Points

  • Oxidoreductases are enzymes that catalyze oxidation-reduction reactions.
  • These reactions involve the transfer of electrons between molecules.
  • Dehydrogenases are a subclass of oxidoreductases that specifically remove hydrogen atoms from substrates.
  • They often use cofactors such as NAD or FAD to accept the electrons or protons.
  • Dehydrogenases play a crucial role in metabolic pathways like glycolysis, the citric acid cycle, and oxidative phosphorylation.

Additional Information

  • Classification of Enzymes
  • Enzymes are classified into six major categories based on the type of reaction they catalyze:
  • Oxidoreductases: Catalyze oxidation-reduction reactions.
  • Transferases: Transfer functional groups between molecules.
  • Hydrolases: Catalyze hydrolysis reactions.
  • Lyases: Break bonds without water or oxidation/reduction involvement.
  • Isomerases: Rearrange atoms within a molecule to form isomers.
  • Ligases: Join two molecules using energy derived from ATP hydrolysis.
  • Role of Dehydrogenases
  • Dehydrogenases are essential in cellular respiration and energy production.
  • Examples include lactate dehydrogenase, which converts pyruvate to lactate, and succinate dehydrogenase, which is part of the citric acid cycle.

Question 107

Xenia denotes the effect of

  1. AOption (a)

    Pollen on endosperm

  2. BOption (b)

    Pollen on egg

  3. COption (c)

    Pollen on nucellus

  4. DOption (d)

    Pollen on seed coat

View answer & explanation

Correct answer

Answer: (a)A.

Pollen on endosperm

Why this answer is correct

The correct answer is - Pollen on endosperm

Key Points

  • Xenia
  • The term Xenia refers to the direct effect of pollen on the characteristics of the endosperm in the seed.
  • It occurs because the endosperm is formed through double fertilization, where one male gamete from the pollen fuses with the two polar nuclei of the embryo sac.
  • Because the pollen contributes genetic material to the endosperm, the paternal genes can immediately influence traits like the color or starch content of the endosperm in the resulting seed.
  • The phenomenon is most commonly observed in Maize (corn), where pollen from a dark-colored variety can change the color of the endosperm in a light-colored variety.

Additional Information

  • Metaxenia
  • Metaxenia is the effect of pollen on the maternal tissues of the fruit or seed coat, which are outside the embryo and endosperm.
  • Examples include the influence of pollen on the size, shape, or ripening time of fruits (like dates or apples).
  • Endosperm
  • In most flowering plants (angiosperms), the endosperm is triploid (3n).
  • It acts as a nutritive tissue that provides food to the developing embryo during seed germination.
  • Maternal Tissues
  • Structures like the nucellus and the seed coat (testa) are purely maternal (sporophytic) tissues.
  • Direct phenotypic changes in these tissues caused by pollen are referred to as metaxenia, not xenia.

Question 108

When micropyle, chalaza and funicle are in a straight line, the ovule is called?

  1. AOption (a)

    Anatropous

  2. BOption (b)

    Campylotropous

  3. COption (c)

    Orthotropous

  4. DOption (d)

    Amphitropous

View answer & explanation

Correct answer

Answer: (c)C.

Orthotropous

Why this answer is correct

The correct answer is - Orthotropous

Key Points

  • Orthotropous Ovule
  • The Orthotropous ovule is considered the most primitive and simplest type of ovule.
  • In this configuration, the micropyle, chalaza, and funicle are all aligned in a straight vertical line.
  • The body of the ovule is straight and not curved or inverted.
  • This type of ovule is commonly found in plants belonging to the families Polygonaceae and Piperaceae, as well as in Gymnosperms like Cycas.

Additional Information

  • Anatropous Ovule
  • This is the most common type of ovule in Angiosperms.
  • The body of the ovule is completely inverted by 180 degrees, causing the micropyle to lie close to the hilum or funicle.
  • Campylotropous Ovule
  • The body of the ovule is curved or bent such that the micropyle and chalaza do not lie in a straight line.
  • The embryo sac, however, remains relatively straight compared to the curved integuments.
  • Amphitropous Ovule
  • The curvature is very prominent, affecting both the ovule body and the embryo sac.
  • The embryo sac becomes horseshoe-shaped, which is a distinguishing feature of this type.
  • Hemianatropous Ovule
  • The body of the ovule is placed transversely or at a right angle (90 degrees) to the funicle.

Question 109

Which of the following is a precursor of coenzyme-A?

  1. AOption (a)

    Pantothenic acid

  2. BOption (b)

    Biotin

  3. COption (c)

    Folic acid

  4. DOption (d)

    Niacin

View answer & explanation

Correct answer

Answer: (a)A.

Pantothenic acid

Why this answer is correct

The correct answer is - Pantothenic acid

Key Points

  • Pantothenic acid
  • Pantothenic acid, commonly known as Vitamin B5, is the primary biological precursor of Coenzyme A (CoA).
  • Coenzyme A is a universal and essential cofactor required for various metabolic pathways, including the TCA cycle (Krebs cycle) and the synthesis and oxidation of fatty acids.
  • The conversion of pantothenic acid to CoA occurs in a five-step process, starting with its phosphorylation by the enzyme pantothenate kinase.

Additional Information

  • Biotin
  • Also known as Vitamin B7, it serves as a prosthetic group for carboxylase enzymes like pyruvate carboxylase, playing a role in gluconeogenesis and fatty acid synthesis.
  • Folic acid
  • Also known as Vitamin B9, it is the precursor for tetrahydrofolate (THF), which is involved in one-carbon transfer reactions necessary for DNA synthesis and amino acid metabolism.
  • Niacin
  • Also known as Vitamin B3, it is the precursor for the coenzymes NAD (Nicotinamide Adenine Dinucleotide) and NADP, which are crucial for electron transfer in redox reactions.

Question 110

Glucose is converted to glucose-6-phosphate by

  1. AOption (a)

    Hexokinase

  2. BOption (b)

    Phosphogluco isomerase

  3. COption (c)

    Phosphofructokinase

  4. DOption (d)

    Phosphotriose isomerase

View answer & explanation

Correct answer

Answer: (a)A.

Hexokinase

Why this answer is correct

The correct answer is - Hexokinase

Key Points

  • Hexokinase
  • The conversion of Glucose to Glucose-6-phosphate is the first primordial step of Glycolysis.
  • This reaction is catalyzed by the enzyme Hexokinase in most tissues (or Glucokinase in the liver and pancreatic beta cells).
  • The process involves the transfer of a phosphate group from ATP to the glucose molecule, effectively trapping the glucose inside the cell.
  • This reaction is irreversible and requires Mg2+ ions as a cofactor.

Additional Information

  • Other Glycolytic Enzymes
  • Phosphogluco isomerase: This enzyme catalyzes the second step of glycolysis, where Glucose-6-phosphate is isomerized into Fructose-6-phosphate.
  • Phosphofructokinase (PFK): This is a key regulatory enzyme that converts Fructose-6-phosphate into Fructose-1,6-bisphosphate using ATP.
  • Phosphotriose isomerase: This enzyme catalyzes the rapid interconversion of the three-carbon sugars Dihydroxyacetone phosphate and Glyceraldehyde-3-phosphate.
  • Glycolysis Overview
  • Glycolysis is a metabolic pathway that breaks down one molecule of glucose into two molecules of Pyruvate.
  • It occurs in the cytoplasm of both prokaryotic and eukaryotic cells and produces a net gain of 2 ATP and 2 NADH molecules.

Question 111

Copper is an essential component of the pigment

  1. AOption (a)

    Anthocyanin

  2. BOption (b)

    Plastocyanin

  3. COption (c)

    Chlorophyll

  4. DOption (d)

    None of the above

View answer & explanation

Correct answer

Answer: (b)B.

Plastocyanin

Why this answer is correct

The correct answer is - Plastocyanin

Key Points

  • Plastocyanin
  • Plastocyanin is a copper-containing protein that functions as a pigment-like electron carrier in the process of photosynthesis.
  • It contains a single copper atom at its active site, which gives the protein a characteristic blue color when in its oxidized state.
  • Its primary role is to transfer electrons from the Cytochrome b6f complex to Photosystem I (PSI) within the thylakoid lumen of chloroplasts.
  • The copper ion in Plastocyanin undergoes redox reactions, cycling between Cu(I) and Cu(II) during electron transport.

Additional Information

  • Chlorophyll
  • Chlorophyll is the primary green pigment in plants responsible for capturing light energy.
  • The essential metal component of chlorophyll is Magnesium (Mg), which is located at the center of its porphyrin ring.
  • Anthocyanin
  • Anthocyanins are water-soluble vacuolar pigments that provide red, purple, or blue colors to flowers and fruits.
  • Unlike Plastocyanin or Chlorophyll, they are organic flavonoids and do not have a specific metal ion like copper as an essential structural component.
  • Importance of Copper in Plants
  • Copper is a vital micronutrient for plants.
  • It is a component of several enzymes such as cytochrome oxidase, polyphenol oxidase, and ascorbic acid oxidase, which are critical for respiration and lignin synthesis.

Question 112

Rapid nutrient cycle occurs in

  1. AOption (a)

    Ocean

  2. BOption (b)

    Grassland

  3. COption (c)

    Coral reef

  4. DOption (d)

    Desert

View answer & explanation

Correct answer

Answer: (b)B.

Grassland

Why this answer is correct

The correct answer is - Grassland

Key Points

  • Grassland
  • In grassland ecosystems, the nutrient cycle is relatively rapid compared to many other ecosystems.
  • This is due to the high rate of decomposition of organic matter and the rapid growth and turnover of herbaceous plants.
  • Nutrients stored in the biomass of grasses are quickly returned to the soil through the decomposition of dead plant parts (litter) and roots.
  • The favorable temperature and moisture conditions during the growing season facilitate intense microbial activity, which accelerates the release of nutrients.

Additional Information

  • Nutrient Cycling
  • Nutrient cycling (also known as biogeochemical cycling) is the movement and exchange of organic and inorganic matter back into the production of living matter.
  • The rate of nutrient cycling depends on the type of ecosystem, climate, and the nature of the decomposing organisms.
  • Comparison with Other Ecosystems
  • Desert: Nutrient cycling is very slow because of the lack of moisture, which limits microbial activity and plant growth.
  • Ocean: While nutrient cycling occurs, it can be slow in many parts because nutrients often sink to the benthic zone (deep ocean) and take a long time to return to the surface via upwelling.
  • Tropical Rainforest: This ecosystem generally has the fastest nutrient cycling due to high temperature and humidity, which lead to almost instantaneous decomposition. Since it is not in the options, Grassland is the most appropriate choice among the terrestrial options provided.
  • Factors Affecting Decomposition
  • Temperature: Higher temperatures generally increase the rate of decomposition.
  • Moisture: Adequate moisture is essential for the survival and activity of decomposers like fungi and bacteria.
  • Litter Quality: Materials rich in nitrogen and low in lignin decompose faster.

Question 113

Molybdenum deficiency affects

  1. AOption (a)

    Nitrogenase activity

  2. BOption (b)

    RUBP-Carboxylase activity

  3. COption (c)

    Malic enzyme activity

  4. DOption (d)

    Hexokinase activity

View answer & explanation

Correct answer

Answer: (a)A.

Nitrogenase activity

Why this answer is correct

The correct answer is - Nitrogenase activity

Key Points

  • Nitrogenase Activity
  • Molybdenum (Mo) is a critical micronutrient required by plants in very small quantities.
  • It is an essential component of the enzyme Nitrogenase, which is responsible for biological nitrogen fixation (converting atmospheric N2 to ammonia).
  • Molybdenum deficiency directly leads to a decrease in Nitrogenase activity, thereby inhibiting the ability of nitrogen-fixing bacteria and legumes to fix nitrogen.

Additional Information

  • Nitrate Reductase
  • Apart from nitrogenase, Molybdenum is also a vital part of the enzyme Nitrate Reductase.
  • This enzyme helps in reducing nitrate to nitrite during the assimilation of nitrogen in all plants.
  • Deficiency Symptoms
  • The most well-known symptom of Molybdenum deficiency is the whiptail disease in cauliflower, where leaf blades fail to develop properly.
  • General symptoms include chlorosis (yellowing) of leaves and inhibited plant growth due to nitrogen starvation.
  • Other Enzyme Activators
  • Magnesium (Mg) is an activator for RUBP-Carboxylase (RuBisCO) and Hexokinase.
  • Manganese (Mn) and Magnesium are involved in the activation of Malic enzyme activity.

Question 114

10% energy transfer law was given by

  1. AOption (a)

    Lindman

  2. BOption (b)

    Kirchner and Schroeter

  3. COption (c)

    Tansley

  4. DOption (d)

    Odum

View answer & explanation

Correct answer

Answer: (a)A.

Lindman

Why this answer is correct

The correct answer is - Lindman

Key Points

  • Lindman
  • The 10% energy transfer law was formulated by Lindman.
  • This law states that only about 10% of the energy at one trophic level is transferred to the next trophic level in a food chain.
  • The remaining energy is lost primarily as heat during metabolic processes.
  • This concept is fundamental in understanding energy flow in ecosystems and the efficiency of energy transfer between trophic levels.

Additional Information

  • Energy flow in ecosystems
  • Energy flow in an ecosystem is unidirectional, moving from producers to consumers and decomposers.
  • At each trophic level, a significant portion of energy is lost as heat, primarily due to respiration and other biological processes.
  • Trophic levels
  • Trophic levels represent the feeding positions in a food chain: producers, primary consumers, secondary consumers, and so on.
  • The 10% energy transfer law explains why there are fewer higher-level consumers compared to producers.
  • Ecological efficiency
  • This refers to the percentage of energy transferred from one trophic level to the next.
  • The 10% rule is a general approximation, with some variability depending on the ecosystem and species involved.

Question 115

What is true for cotton fibres ?

  1. AOption (a)

    Epidermal prolongation of seed coat

  2. BOption (b)

    Elongation of cortex cells

  3. COption (c)

    Elongation of cambial cells

  4. DOption (d)

    Elongation of phloem cells

View answer & explanation

Correct answer

Answer: (a)A.

Epidermal prolongation of seed coat

Why this answer is correct

The correct answer is - Epidermal prolongation of seed coat

Key Points

  • Cotton Fibres
  • Cotton fibres are technically epidermal hairs or trichomes that arise from the outer integument (testa) of the seed coat.
  • They are unicellular outgrowths that undergo massive elongation during the development of the seed.
  • These fibres are categorized as surface fibres because they grow on the surface of plant organs (seeds) rather than being part of the vascular bundles or inner tissues.

Additional Information

  • Composition and Types
  • The mature cotton fibre consists of nearly 90% cellulose, which provides it with high strength and durability.
  • Cotton seeds produce two types of fibres: Lint (long, commercially important fibres) and Fuzz (short fibres or linters remaining on the seed after ginning).
  • Comparison with other Plant Fibres
  • Bast Fibres: Fibres like Jute, Flax, and Hemp are derived from the phloem or pericycle of the stem. These are sclerenchymatous cells, unlike the epidermal origin of cotton.
  • Cortex and Cambium: Fibres are generally not derived from the elongation of cortex or cambial cells in a way that produces textile-grade surface hairs like cotton.
  • Economic Importance
  • Because cotton is an epidermal prolongation, it is easily separated from the seed during the ginning process, making it the most widely used natural fibre for textile production globally.

Question 116

Asafoetida (Hing) is obtained from

  1. AOption (a)

    Leaf extract

  2. BOption (b)

    Seeds

  3. COption (c)

    Inflorescene extract

  4. DOption (d)

    Resinous exudates from roots

View answer & explanation

Correct answer

Answer: (d)D.

Resinous exudates from roots

Why this answer is correct

The correct answer is - Resinous exudates from roots

Key Points

  • Source of Asafoetida (Hing)
  • Asafoetida is an oleo-gum-resin obtained from the exudates of the thick, fleshy roots or rhizomes of several species of Ferula.
  • The resin is collected by making incisions in the living taproots of the plants, typically after the stem is cut close to the ground.
  • The milky juice that exudes from the cut surface dries into a resinous mass, which is then collected.

Additional Information

  • Botanical Background
  • It belongs to the family Apiaceae (also known as Umbelliferae).
  • The most common species used for production is Ferula asafoetida.
  • These plants are perennial herbs native to the deserts of Iran and the mountains of Afghanistan.
  • Properties and Uses
  • It has a strong, pungent smell due to the presence of volatile sulfur compounds.
  • In India, it is popularly known as Hing and is widely used as a spice in cooking for its flavor and digestive properties.
  • Medicinally, it is used to treat flatulence, asthma, and bronchitis due to its anti-inflammatory and antimicrobial activities.
  • Chemical Composition
  • Asafoetida consists of approximately 40-64% resin, 25% endogenous gum, and 10-17% volatile oil.
  • The characteristic aroma is primarily attributed to secondary butyl-propenyl disulfide.

Question 117

Nemec phenomenon refers to

  1. AOption (a)

    occurrence of pollen embryo sac

  2. BOption (b)

    fusion of antipodal cells

  3. COption (c)

    occurrence of synergid embryo

  4. DOption (d)

    development of embryo without fertilisation

View answer & explanation

Correct answer

Answer: (a)A.

occurrence of pollen embryo sac

Why this answer is correct

The correct answer is - occurrence of pollen embryo sac

Key Points

  • Nemec Phenomenon
  • The Nemec phenomenon refers to the occurrence of pollen embryo sacs, a process where a microspore (pollen grain) develops into an 8-nucleated embryo-sac-like structure.
  • It was first discovered by B. Nemec (1898) in the petaloid anthers of Hyacinthus orientalis.
  • This phenomenon represents an unusual developmental pathway where the male gametophyte (pollen) mimics the structural organization of the female gametophyte (embryo sac).

Additional Information

  • Mechanism of Formation
  • Under certain conditions, such as the degeneration of the tapetum or physiological stress, the microspore enlarges significantly.
  • The microspore nucleus undergoes three mitotic divisions to produce eight nuclei, which arrange themselves in a manner similar to the Polygonum type of embryo sac.
  • The resulting structure typically contains an egg-like cell, two synergids, three antipodal cells, and two polar nuclei.
  • Significance
  • This phenomenon is a classic example of totipotency, where a cell destined to become a male gamete changes its developmental fate to resemble a female gametophyte.
  • While these pollen embryo sacs are structurally similar to female embryo sacs, they are generally non-functional and do not participate in normal fertilization.
  • Other Options Explained
  • Fusion of antipodal cells: This is not a specific named phenomenon; antipodal cells usually degenerate after fertilization.
  • Synergid embryo: This refers to apogamy, where an embryo develops from a synergid without fertilization.
  • Development of embryo without fertilisation: This is generally termed Apomixis or Parthenogenesis.

Question 118

The enzyme involved in nitrogen fixation is

  1. AOption (a)

    Nitrogenase and reductase

  2. BOption (b)

    Nitrogenylase only

  3. COption (c)

    Oxidase and reductase

  4. DOption (d)

    Reductase only

View answer & explanation

Correct answer

Answer: (a)A.

Nitrogenase and reductase

Why this answer is correct

The correct answer is - Nitrogenase and reductase

Key Points

  • Nitrogenase Enzyme Complex
  • Biological nitrogen fixation is primarily carried out by the nitrogenase enzyme complex.
  • This complex is composed of two main protein components: dinitrogenase (containing Molybdenum and Iron) and dinitrogenase reductase (containing Iron).
  • The reductase component (Fe-protein) serves as the electron donor to the dinitrogenase component (MoFe-protein), which then reduces the atmospheric nitrogen (N2) to ammonia (NH3).

Additional Information

  • Biological Nitrogen Fixation (BNF)
  • It is the process where atmospheric nitrogen is converted into ammonia by specialized microorganisms known as diazotrophs.
  • This process is vital for life as nitrogen is a key component of amino acids, proteins, and nucleic acids.
  • Oxygen Sensitivity
  • The enzyme nitrogenase is highly sensitive to oxygen; it is irreversibly inactivated in its presence.
  • To protect this enzyme, organisms use various strategies, such as leghemoglobin in legume root nodules, which acts as an oxygen scavenger.
  • Energy Requirement
  • Nitrogen fixation is an energy-intensive process.
  • For every molecule of nitrogen fixed, approximately 16 molecules of ATP are consumed to provide the necessary energy for the chemical reduction.

Question 119

The insecticide pyrethrin is obtained from

  1. AOption (a)

    Nicotiana rustica

  2. BOption (b)

     Ageratum conyzoides

  3. COption (c)

    Azadirachta indica

  4. DOption (d)

    Chrysanthemum cinerariafolium

View answer & explanation

Correct answer

Answer: (d)D.

Chrysanthemum cinerariafolium

Why this answer is correct

The correct answer is - Chrysanthemum cinerariafolium

Key Points

  • Chrysanthemum cinerariafolium
  • Pyrethrin is a natural insecticide obtained primarily from the dried flower heads of Chrysanthemum cinerariafolium (often called the Pyrethrum daisy).
  • The active insecticidal components are located in the achenes (seed-like fruits) of the flower.
  • It is widely used in organic farming and household insect sprays because it is highly effective against pests like mosquitoes, houseflies, and aphids.

Additional Information

  • Mode of Action
  • Pyrethrins are neurotoxins that target the nervous system of insects.
  • They work by keeping sodium channels open in the nerve cells, leading to hyperexcitation, paralysis, and eventually the death of the insect (often referred to as the 'knockdown' effect).
  • Environmental Safety
  • One of the biggest advantages of pyrethrin is that it is biodegradable and breaks down quickly upon exposure to sunlight and air.
  • It has relatively low toxicity to mammals and birds, making it safer for domestic use compared to many synthetic pesticides.
  • Other Botanical Insecticides
  • Azadirachta indica (Neem): Produces Azadirachtin, which acts as an antifeedant and growth disruptor for insects.
  • Nicotiana rustica (Tobacco): Contains Nicotine, a powerful alkaloid used as a contact insecticide, though it is much more toxic to humans than pyrethrins.
  • Ageratum conyzoides: Known as billygoat-weed, it contains compounds with some insect-repellent properties but is not the commercial source of pyrethrin.

Question 120

The species of plants which belong to same ecological stock but differ genetically are called

  1. AOption (a)

    Ecotone

  2. BOption (b)

    Ecotype

  3. COption (c)

    Ecasis

  4. DOption (d)

    Ecological equivalents

View answer & explanation

Correct answer

Answer: (a)A.

Ecotone

Why this answer is correct

The correct answer is - Ecotype

Key Points

  • Ecotype
  • An Ecotype is a genetically distinct geographic variety, population, or race within a species, which is adapted to specific environmental conditions.
  • They belong to the same ecological stock (same species) but have undergone genetic changes to survive in their specific habitat.
  • These genetic variations are inheritable and remain even if the plant is moved to a different environment.
  • Turesson coined the term to describe the genetic response of a species to a particular habitat.

Additional Information

  • Ecotone
  • An Ecotone is a transition area between two biological communities or ecosystems, such as the area between a forest and a grassland.
  • It often contains species from both adjacent ecosystems and may have a higher biodiversity, known as the Edge Effect.
  • Ecasis
  • Ecasis (or ecesis) refers to the successful establishment of a plant or animal species in a new habitat.
  • It is a stage in Ecological Succession where the migrant species starts to grow and reproduce in the new area.
  • Ecological Equivalents
  • These are organisms that occupy similar niches in different geographical regions.
  • For example, kangaroos in Australia and bison in North America both play the role of large grazers in their respective grasslands despite being different species.

Question 121

Ligase enzyme is used for

  1. AOption (a)

    Splitting of DNA

  2. BOption (b)

    Joining bits of DNA

  3. COption (c)

    Lignin synthesis

  4. DOption (d)

     Denaturation of DNA 

View answer & explanation

Correct answer

Answer: (a)A.

Splitting of DNA

Why this answer is correct

The correct answer is - Joining bits of DNA

Key Points

  • Ligase enzyme
  • Ligase is a specific enzyme that facilitates the joining of DNA fragments by forming phosphodiester bonds.
  • It is crucial in processes such as DNA replication and DNA repair.
  • Ligase is commonly used in molecular biology techniques, such as genetic engineering, to link DNA segments during cloning.

Additional Information

  • DNA replication
  • During DNA replication, ligase seals the gaps between Okazaki fragments on the lagging strand, ensuring continuity of the DNA strand.
  • DNA repair
  • In DNA repair mechanisms, ligase aids in restoring the integrity of the DNA by sealing breaks or nicks in the phosphodiester backbone.
  • Applications in genetic engineering
  • Ligase is utilized in recombinant DNA technology to join DNA fragments from different sources, enabling the creation of genetically modified organisms (GMOs).
  • It is also employed in techniques like polymerase chain reaction (PCR) for amplifying specific DNA sequences.

Question 122

Sigma factor is a component of

  1. AOption (a)

    DNA  ligase

  2. BOption (b)

    Endonuclease

  3. COption (c)

    DNA Polymerase

  4. DOption (d)

    RNA Polymerase

View answer & explanation

Correct answer

Answer: (d)D.

RNA Polymerase

Why this answer is correct

The correct answer is - R.N.A. Polymerase

Key Points

  • Sigma Factor
  • The Sigma factor (σ factor) is a protein essential for the initiation of transcription in prokaryotic organisms.
  • It is a specific subunit of R.N.A. Polymerase that provides the catalytic core with the ability to recognize and bind to promoter sequences on D.N.A.
  • The primary role of the sigma factor is to ensure that transcription begins at the correct site, facilitating the local unwinding of the D.N.A. helix.

Additional Information

  • Holoenzyme and Core Enzyme
  • In bacteria, R.N.A. Polymerase exists in two forms: the Core Enzyme and the Holoenzyme.
  • The Core Enzyme (composed of α2ββ'ω subunits) can synthesize R.N.A. but cannot initiate transcription accurately.
  • The Holoenzyme is formed when the sigma factor associates with the core enzyme, allowing for promoter-specific initiation.
  • Other Enzymes mentioned
  • D.N.A. Polymerase: This enzyme is responsible for D.N.A. replication, synthesizing a new D.N.A. strand using an existing template.
  • D.N.A. Ligase: Known as the 'molecular glue,' it facilitates the joining of D.N.A. strands together by catalyzing the formation of phosphodiester bonds.
  • Endonuclease: These are enzymes that cleave the phosphodiester bond within a polynucleotide chain, playing a major role in D.N.A. repair and restriction mapping.
  • Transcription Process
  • Once the R.N.A. chain reaches a certain length (approximately 8-10 nucleotides), the sigma factor is usually released from the complex.
  • The core enzyme then continues the elongation phase of transcription independently.

Question 123

The diameter of Z-DNA is

  1. AOption (a)

     34 Å

  2. BOption (b)

    20 Å

  3. COption (c)

    18 Å

  4. DOption (d)

    45 Å

View answer & explanation

Correct answer

Answer: (c)C.

18 Å

Why this answer is correct

The correct answer is - 18 Å

Key Points

  • Z-DNA Diameter
  • Z-DNA is a left-handed double helical structure of DNA.
  • The diameter of Z-DNA is approximately 18 Å.
  • It is the thinnest known form of DNA compared to the A and B forms.
  • The name 'Z' comes from the zig-zag pattern of its sugar-phosphate backbone.

Additional Information

  • Comparison with B-DNA
  • B-DNA is the most common form of DNA found in nature; it is a right-handed helix with a diameter of 20 Å.
  • While B-DNA has a pitch (height of one complete turn) of 34 Å, Z-DNA has a pitch of 45 Å.
  • B-DNA contains about 10 base pairs per turn, whereas Z-DNA contains 12 base pairs per turn.
  • Structural Features of Z-DNA
  • Z-DNA often forms in sequences where purines and pyrimidines alternate, such as poly(dGC).poly(dGC).
  • It is believed to play a role in gene regulation and relieving torsional strain during transcription.
  • A-DNA
  • A-DNA is also a right-handed helix but is wider and shorter than B-DNA, with a diameter of about 23 Å.

Question 124

Which of the following is not used in PCR?

  1. AOption (a)

    Taq polymerase

  2. BOption (b)

    Restriction enzymes

  3. COption (c)

    Oligonucleotide primers

  4. DOption (d)

    Deoxynucleoside triphosphate

View answer & explanation

Correct answer

Answer: (b)B.

Restriction enzymes

Why this answer is correct

The correct answer is - Restriction enzymes

Key Points

  • Restriction enzymes
  • Restriction enzymes are used to cut DNA at specific sequences, typically in cloning or genetic engineering experiments.
  • They are not involved in the Polymerase Chain Reaction (PCR) process, which focuses on amplifying DNA.
  • Unlike PCR components, restriction enzymes do not play a role in synthesizing or extending DNA strands.
  • Taq polymerase
  • A thermostable enzyme derived from Thermus aquaticus, Taq polymerase is essential for DNA amplification in PCR.
  • Oligonucleotide primers
  • Primers are short, single-stranded sequences that bind to complementary DNA and guide the extension process during PCR.
  • Deoxynucleoside triphosphates (dNTPs)
  • dNTPs act as building blocks for new DNA strand synthesis during PCR.

Additional Information

  • PCR process
  • Polymerase Chain Reaction (PCR) is a technique used to amplify specific DNA sequences exponentially.
  • The key steps include denaturation (separating DNA strands), annealing (binding primers), and extension (synthesizing DNA).
  • Applications of PCR
  • PCR is widely used in molecular biology, medical diagnostics, and forensic science.
  • It helps in detecting genetic mutations, identifying pathogens, and DNA profiling.
  • Restriction enzymes in genetic engineering
  • Restriction enzymes are commonly used in recombinant DNA technology to cut DNA at specific sites.
  • They are essential for cloning DNA fragments into vectors but are not required for PCR.

Question 125

Peptide synthesis inside cell usually takes place in

  1. AOption (a)

    Mitochondria

  2. BOption (b)

    Chromoplast

  3. COption (c)

    Ribosomes

  4. DOption (d)

    Golgi bodies

View answer & explanation

Correct answer

Answer: (c)C.

Ribosomes

Why this answer is correct

The correct answer is - Ribosomes

Key Points

  • Ribosomes
  • Ribosomes are the primary sites for peptide synthesis (protein synthesis) in all living cells.
  • They facilitate the process of translation, where the genetic code carried by mRNA is decoded to link amino acids into a polypeptide chain.
  • Ribosomes can be found floating freely in the cytoplasm or attached to the Rough Endoplasmic Reticulum (RER) in eukaryotic cells.
  • They are often referred to as the protein factories of the cell because they are essential for creating proteins required for various cellular functions.

Additional Information

  • Mitochondria
  • Known as the powerhouse of the cell, mitochondria are primarily responsible for producing ATP through cellular respiration.
  • While they contain their own ribosomes for synthesizing a few of their own proteins, they are not the primary site for general cellular peptide synthesis.
  • Chromoplast
  • Chromoplasts are a type of plastid found in plant cells that are responsible for the synthesis and storage of pigments (like carotenoids).
  • They give color to fruits, flowers, and aging leaves but are not involved in protein synthesis.
  • Golgi bodies
  • The Golgi apparatus is involved in modifying, sorting, and packaging proteins and lipids that have already been synthesized.
  • It acts like a post office, preparing these molecules for secretion or delivery to other organelles, rather than building the peptide chains themselves.

Question 126

DNA replication takes place at

  1. AOption (a)

    G1 Phase

  2. BOption (b)

    S Phase

  3. COption (c)

    G2 Phase

  4. DOption (d)

    Interphase

View answer & explanation

Correct answer

Answer: (b)B.

S Phase

Why this answer is correct

The correct answer is - S Phase

Key Points

  • S Phase (Synthesis Phase)
  • The S phase is the specific period during the cell cycle when DNA replication takes place.
  • During this stage, the amount of DNA per cell doubles (e.g., from 2C to 4C), ensuring that each daughter cell receives a complete set of genetic instructions.
  • Importantly, while the DNA content doubles, the chromosome number remains the same (remains 2n).
  • In animal cells, the centriole also duplicates in the cytoplasm during this phase.

Additional Information

  • The Cell Cycle
  • The cell cycle is divided into two main phases: Interphase and M Phase (Mitosis).
  • Interphase is known as the resting phase but is metabolically very active. It is divided into:
  • G1 Phase (Gap 1): The interval between mitosis and DNA replication where the cell grows and is metabolically active.
  • S Phase (Synthesis): Period of DNA synthesis.
  • G2 Phase (Gap 2): Period where proteins are synthesized in preparation for mitosis while cell growth continues.
  • M Phase
  • This is the actual phase of cell division where the replicated DNA is distributed to daughter nuclei (karyokinesis) followed by the division of cytoplasm (cytokinesis).

Question 127

Incomplete dominance is present in

  1. AOption (a)

    Lathyrus odoratus

  2. BOption (b)

    Mirabilis jalapa

  3. COption (c)

    Pisum sativum

  4. DOption (d)

    Oenothera lamarckiana

View answer & explanation

Correct answer

Answer: (b)B.

Mirabilis jalapa

Why this answer is correct

The correct answer is - Mirabilis jalapa

Key Points

  • Mirabilis jalapa
  • Commonly known as the four o clock plant, it is a classic example used to demonstrate incomplete dominance.
  • In this plant, when a pure-breeding red-flowered plant (RR) is crossed with a pure-breeding white-flowered plant (rr), the resulting F1 generation produces pink flowers (Rr).
  • This happens because the dominant allele (R) is not completely dominant over the recessive allele (r), resulting in an intermediate phenotype.

Additional Information

  • Incomplete Dominance
  • It is a form of intermediate inheritance where neither allele is completely dominant over the other.
  • The phenotypic ratio and genotypic ratio in the F2 generation are the same: 1:2:1 (1 Red : 2 Pink : 1 White).
  • It was first described by Carl Correns based on his work with Mirabilis jalapa.
  • Other Examples
  • Antirrhinum majus (Snapdragon or Dog flower) also exhibits incomplete dominance in flower color.
  • In Andalusian fowls, the cross between black and white feathered birds results in blue-feathered offspring.
  • Comparison with other plants
  • Pisum sativum (Garden Pea): Used by Mendel to demonstrate Complete Dominance.
  • Lathyrus odoratus (Sweet Pea): Known for showing complementary gene action and linkage.
  • Oenothera lamarckiana (Evening Primrose): Used by Hugo de Vries to propose the Mutation Theory.

Question 128

First transgenic plant was developed in

  1. AOption (a)

    Pea

  2. BOption (b)

    Cotton

  3. COption (c)

    Tobacco

  4. DOption (d)

    Rice

View answer & explanation

Correct answer

Answer: (c)C.

Tobacco

Why this answer is correct

The correct answer is - Tobacco

Key Points

  • Tobacco was the first plant successfully engineered to be transgenic.
  • In 1983, researchers developed a transgenic Tobacco plant by introducing a foreign gene using Agrobacterium tumefaciens, a bacterium known for its ability to transfer genetic material into plants.
  • This breakthrough demonstrated that it was possible to introduce foreign DNA into plant genomes and express it successfully.
  • The success of the experiment paved the way for the development of genetically modified crops with improved traits such as pest resistance and increased yield.

Additional Information

  • Transgenic plants
  • These are plants that have been genetically engineered to contain one or more genes from another species.
  • They are developed to exhibit desirable traits such as herbicide tolerance, insect resistance, and disease resistance.
  • Agrobacterium tumefaciens
  • This bacterium naturally transfers part of its DNA, known as the T-DNA, into plant cells, causing crown gall disease.
  • It has been harnessed as a tool in genetic engineering to introduce desired genes into plants.
  • Applications of transgenic plants
  • Production of genetically modified crops such as Bt cotton for pest resistance.
  • Development of crops with improved nutritional value, such as Golden Rice, which is rich in Vitamin A.

Question 129

Which of the following is terminator codon in genetic code?

  1. AOption (a)

    UGA

  2. BOption (b)

    UCG

  3. COption (c)

    UUC

  4. DOption (d)

    UCU

View answer & explanation

Correct answer

Answer: (a)A.

UGA

Why this answer is correct

The correct answer is - UGA

Key Points

  • Terminator Codon
  • A terminator codon (or stop codon) is a specific sequence of three nucleotides in mRNA that signals the end of protein synthesis (translation).
  • There are three standard terminator codons in the universal genetic code: UAA (Ochre), UAG (Amber), and UGA (Opal).
  • Among the given options, UGA is a terminator codon.
  • These codons do not code for any amino acid; instead, they lead to the binding of release factors which trigger the dissociation of the translation complex.

Additional Information

  • Genetic Code Basics
  • The genetic code is a triplet code, meaning three nitrogenous bases form one codon.
  • There are 64 codons in total: 61 sense codons (coding for amino acids) and 3 stop codons.
  • AUG is known as the start codon because it initiates the process of translation and also codes for the amino acid Methionine.
  • Characteristics of the Genetic Code
  • Universal: The same codons code for the same amino acids in almost all organisms, from bacteria to humans.
  • Degenerate: Many amino acids are specified by more than one codon (e.g., UCU, UCC, UCA, and UCG all code for Serine).
  • Non-overlapping: The code is read in a continuous sequence of triplets without sharing bases between adjacent codons.
  • Other Options Explained
  • UCG: Codes for the amino acid Serine.
  • UUC: Codes for the amino acid Phenylalanine.
  • UCU: Codes for the amino acid Serine.

Question 130

Which of the following enzymes is active above 90°C?

  1. AOption (a)

    ATP synthetase

  2. BOption (b)

    Taq polymerase

  3. COption (c)

    Peroxidase

  4. DOption (d)

    Cytochrome oxidase

View answer & explanation

Correct answer

Answer: (b)B.

Taq polymerase

Why this answer is correct

The correct answer is - Taq polymerase

Key Points

  • Taq polymerase
  • Taq polymerase is a thermostable DNA polymerase named after the thermophilic bacterium Thermus aquaticus.
  • It is capable of remaining active at high temperatures, typically withstanding temperatures above 90°C.
  • Its primary application is in the Polymerase Chain Reaction (PCR), where it is used to automate the repetitive process of amplifying specific DNA sequences.
  • Unlike most enzymes that denature at high temperatures, Taq polymerase remains stable during the denaturation step of PCR, which usually occurs at around 94-95°C.

Additional Information

  • Thermus aquaticus
  • This bacterium was first discovered in hot springs in Yellowstone National Park.
  • Its enzymes are evolved to function optimally in extreme heat, which led to the revolutionary development of modern molecular biology techniques.
  • Polymerase Chain Reaction (PCR)
  • PCR involves three main steps: Denaturation (high heat), Annealing (lowering temperature for primers), and Extension (DNA synthesis).
  • Before the use of Taq polymerase, scientists had to manually add fresh DNA polymerase (like E. coli polymerase) after every heating cycle because the heat destroyed the enzyme.
  • Other Enzymes mentioned
  • ATP synthetase: Involved in the synthesis of ATP in mitochondria and chloroplasts; typically functions at physiological temperatures.
  • Peroxidase: An enzyme that catalyzes the oxidation of various compounds by hydrogen peroxide; generally found in plants and animals.
  • Cytochrome oxidase: The final enzyme in the electron transport chain of cellular respiration; it is sensitive to high temperatures.

Question 131

How many female flowers are found in a cyathium?

  1. AOption (a)

    one

  2. BOption (b)

    two

  3. COption (c)

    three

  4. DOption (d)

    many

View answer & explanation

Correct answer

Answer: (a)A.

one

Why this answer is correct

Code

**The correct answer is - one**

 Key Points

- **Cyathium**
- A cyathium is a specialized inflorescence found in plants of the **Euphorbiaceae** family, such as poinsettias and spurges.
- It consists of a cup-like structure that houses multiple flowers.
- **Female flower in a cyathium**
- Within the cyathium, there is only **one** female flower.
- The female flower is positioned centrally and is distinguished by its **long stalk** (gynophore).
- **Male flowers in a cyathium**
- Unlike the single female flower, the male flowers are **numerous** and surround the female flower.
- Each male flower typically consists of a single stamen.

 Additional Information

- **Characteristics of a cyathium**
- The entire structure is surrounded by **bracts**, which often resemble petals and attract pollinators.
- The arrangement within the cyathium ensures **efficient pollination**, often facilitated by insects.
- **Function of the female flower**
- The single female flower is responsible for **seed production** after successful pollination.
- It contains a **tricarpellary ovary** with a superior position.
- **Examples of plants with cyathium**
- Common examples include **Euphorbia** species like poinsettia (*Euphorbia pulcherrima*) and crown of thorns (*Euphorbia milii*).

Question 132

Total number of series in Bentham and Hooker's system of classification is

  1. AOption (a)

    09

  2. BOption (b)

    15

  3. COption (c)

    18

  4. DOption (d)

    21

View answer & explanation

Correct answer

Answer: (a)A.

09

Why this answer is correct

The correct answer is - Total number of series in Bentham and Hooker's system of classification is 9

Key Points

  • Bentham and Hooker's system of classification
  • Bentham and Hooker classified plants into three classes: Dicotyledons, Gymnosperms, and Monocotyledons.
  • These classes are further divided into series, which represent groups based on evolutionary relationships.
  • The system contains a total of 9 series, which include diverse groups of plants.
  • Series details
  • The series are based on morphological and structural characteristics.
  • Examples of series include Thalamiflorae (flowers with free sepals and petals) and Inferae (flowers with inferior ovaries).

Additional Information

  • Classification hierarchy
  • The Bentham and Hooker system divides plants into classes, series, orders, and families.
  • It is a natural system of classification based on overall similarities in morphology.
  • Significance
  • This system is widely used for studying plant taxonomy and serves as a foundation for modern classification systems.
  • Though it is an older system, it provides a detailed and systematic arrangement of plants.

Question 133

Rice fruit is

  1. AOption (a)

    Achene

  2. BOption (b)

    Caruncle

  3. COption (c)

    Caryopsis

  4. DOption (d)

    Cypsella

View answer & explanation

Correct answer

Answer: (c)C.

Caryopsis

Why this answer is correct

The correct answer is - Caryopsis

Key Points

  • Caryopsis
  • Rice (Oryza sativa) belongs to the Poaceae (Gramineae) family, and its fruit is known as a Caryopsis.
  • A Caryopsis is a type of dry indehiscent fruit that contains only one seed.
  • The defining characteristic of a caryopsis is that the pericarp (fruit wall) is completely fused with the testa (seed coat), making it difficult to separate the seed from the fruit wall.
  • This fruit type is commonly referred to as a grain and is typical of cereals like wheat, maize, and rice.

Additional Information

  • Achene
  • An achene is also a dry indehiscent one-seeded fruit, but unlike the caryopsis, the seed coat is free from the pericarp.
  • Examples include buckwheat and the small brown 'seeds' on the surface of a strawberry.
  • Cypsella
  • This is a dry, one-seeded indehiscent fruit that develops from a bicarpellary inferior ovary.
  • It is characteristic of the Asteraceae (sunflower) family and often features a pappus (hair-like structures) to assist in wind dispersal.
  • Caruncle
  • A caruncle is not a type of fruit; rather, it is a fleshy outgrowth or appendage of the seed coat (testa) found near the hilum.
  • It is commonly seen in seeds like Castor (Ricinus communis) and helps in water absorption and seed dispersal by ants.
  • Economic Importance
  • Caryopsis fruits are the primary source of carbohydrates for the global population, as they include all major cereal crops.

Question 134

Floral buds are modified into tendril in

  1. AOption (a)

    Antigonon

  2. BOption (b)

    Bignonia

  3. COption (c)

    Cleome

  4. DOption (d)

    Smilax

View answer & explanation

Correct answer

Answer: (a)A.

Antigonon

Why this answer is correct

The correct answer is - Antigonon

Key Points

  • Floral buds modification
  • In Antigonon, the floral buds are modified into tendrils.
  • This adaptation helps the plant in climbing and providing support for growth.
  • Tendrils are slender, coiled structures that twine around objects, enabling the plant to anchor itself.
  • Role of tendrils
  • Tendrils aid in mechanical support, especially in plants that grow in areas with limited structural support.
  • They are a common feature in climbing plants like Antigonon, which use them to stabilize against external forces like wind.

Additional Information

  • Other modifications of plant parts
  • In Bignonia, leaves are modified into tendrils for climbing.
  • In Smilax, stipules are modified into tendrils.
  • In Cleome, there is no modification into tendrils; it is an erect herbaceous plant.
  • Types of tendrils
  • Stem tendrils: Modified stems or branches, e.g., in grapevine.
  • Leaf tendrils: Modified leaves or leaflets, e.g., in pea plants.

Question 135

Tricarpellary, syncarpous and superior ovary is found in

  1. AOption (a)

    Fabaceae

  2. BOption (b)

    Ranunculaceae

  3. COption (c)

    Liliaceae

  4. DOption (d)

    Poaceae

View answer & explanation

Correct answer

Answer: (c)C.

Liliaceae

Why this answer is correct

The correct answer is - Liliaceae

Key Points

  • Liliaceae
  • The family Liliaceae, commonly called the Lily family, is a characteristic representative of monocotyledonous plants.
  • The gynoecium of this family is tricarpellary (three carpels), syncarpous (fused carpels), and the ovary is superior.
  • The ovary is usually trilocular with many ovules and exhibits axile placentation.

Additional Information

  • Fabaceae
  • The gynoecium is monocarpellary, superior, unilocular with many ovules, and the style is single.
  • Poaceae
  • The gynoecium is usually monocarpellary (functionally), the ovary is superior and unilocular, typically with a single ovule and basal placentation.
  • Floral Formula of Liliaceae
  • The general floral formula is Br ⊕ ⚥ P(3+3) A3+3 G(3).
  • The G(3) symbol specifically denotes that the ovary is superior (underlined G), tricarpellary (number 3), and syncarpous (brackets around 3).
  • Ranunculaceae
  • Plants in this family generally have a gynoecium that is multicarpellary and apocarpous (carpels are free), which distinguishes it from the syncarpous condition of Liliaceae.

Question 136

Ochreate stipules are found in

  1. AOption (a)

    Fumariaceae

  2. BOption (b)

    Lamiaceae

  3. COption (c)

    Acanthaceae

  4. DOption (d)

    Polygonaceae

View answer & explanation

Correct answer

Answer: (a)A.

Fumariaceae

Why this answer is correct

The correct answer is - Polygonaceae

Key Points

  • Ochreate stipules
  • Ochreate stipules are a characteristic feature found in plants belonging to the Polygonaceae family.
  • An ochrea is a sheath-like structure formed from the fusion of stipules and typically surrounds the stem at the node.
  • This unique adaptation is commonly observed in genera such as Polygonum and Rumex within the Polygonaceae family.
  • Family identification
  • The presence of ochreate stipules is a key morphological trait used in the taxonomy and classification of the Polygonaceae family.
  • It distinguishes Polygonaceae from other families such as Fumariaceae, Lamiaceae, and Acanthaceae, which lack this feature.

Additional Information

  • Polygonaceae Family
  • Commonly known as the knotweed family, Polygonaceae includes approximately 50 genera and over 1,200 species.
  • Species in this family are typically herbaceous, although some are shrubs or climbers.
  • Other notable features
  • Leaves are generally simple, alternate, and often accompanied by ochreate stipules.
  • Flowers are small, actinomorphic, and arranged in spikes or racemes.
  • Fruit is typically an achene, often three-angled or winged.
  • Comparison with other families
  • Fumariaceae: Known for compound leaves and irregular flowers, lacks ochreate stipules.
  • Lamiaceae: Aromatic herbs with quadrangular stems and opposite leaves, no ochreate stipules.
  • Acanthaceae: Contains bracteate flowers and opposite leaves, but no stipule fusion.

Question 137

Which of the following is an example of saprophytic angiosperms ?

  1. AOption (a)

    Cuscuta

  2. BOption (b)

    Avicinea

  3. COption (c)

    Nepenthes

  4. DOption (d)

    Monotropa

View answer & explanation

Correct answer

Answer: (d)D.

Monotropa

Why this answer is correct

The correct answer is - Monotropa

Key Points

  • Monotropa
  • Monotropa (commonly known as Indian Pipe) is a classic example of a saprophytic angiosperm.
  • These plants are achlorophyllous, meaning they lack chlorophyll and cannot perform photosynthesis to produce their own food.
  • They obtain nutrition from dead and decaying organic matter. More specifically, they are mycoheterotrophs, obtaining nutrients through a fungal association linked to the roots of nearby trees.
  • Because they do not need sunlight for energy, they are often found in the deep shade of dense forests.

Additional Information

  • Cuscuta (Dodder)
  • It is a parasitic plant that lacks chlorophyll and leaves.
  • It uses haustoria to penetrate the vascular tissues of a host plant to absorb water and nutrients.
  • Nepenthes (Pitcher Plant)
  • It is an insectivorous plant (carnivorous).
  • It performs photosynthesis but grows in nitrogen-deficient soil. To fulfill its nitrogen requirement, it traps and digests insects using pitcher-shaped leaves.
  • Avicennia
  • It is a genus of mangrove plants (halophytes) found in coastal saline environments.
  • They possess specialized roots called pneumatophores (breathing roots) to help in gas exchange in waterlogged, anaerobic soil.
  • Saprophytes vs. Parasites
  • Saprophytes feed on dead organic matter, whereas Parasites live on or inside a living host and derive nutrients at the host's expense.

Question 138

Myrosin glands are found in

  1. AOption (a)

    Brassicaceae

  2. BOption (b)

    Malvaceae

  3. COption (c)

    Oleaceae

  4. DOption (d)

    Rutaceae

View answer & explanation

Correct answer

Answer: (a)A.

Brassicaceae

Why this answer is correct

The correct answer is - Brassicaceae

Key Points

  • Myrosin Glands
  • Myrosin glands (also known as myrosin cells) are specialized idioblasts containing the enzyme myrosinase.
  • These glands are a characteristic feature of the family Brassicaceae (formerly known as Cruciferae), which includes plants like mustard, radish, and cabbage.
  • The myrosinase enzyme is involved in the hydrolysis of glucosinolates. When plant tissues are crushed or damaged, the enzyme reacts with the glucosinolates to produce pungent isothiocyanates (mustard oils).
  • This system acts as a potent chemical defense mechanism against herbivores and pathogens.

Additional Information

  • Rutaceae
  • This family (e.g., Lemon, Orange) is characterized by the presence of lysigenous oil glands or cavities that secrete aromatic volatile oils.
  • Malvaceae
  • Commonly known as the mallow family (e.g., Hibiscus, Cotton), these plants are characterized by mucilage canals and monadelphous stamens.
  • Oleaceae
  • This family (e.g., Jasmine, Olive) is known for plants having two stamens and usually containing phenolic glycosides, but they do not possess myrosin glands.
  • Brassicaceae Identification
  • Apart from myrosin glands, this family is identified by its cruciform corolla (four petals arranged like a cross) and tetradynamous stamens (six stamens: four long and two short).

Question 139

Smallest gymnosperm is

  1. AOption (a)

    Zamia pygmea

  2. BOption (b)

    Gnetum ula

  3. COption (c)

    Gnetum africana

  4. DOption (d)

    Ephedra viridis

View answer & explanation

Correct answer

Answer: (a)A.

Zamia pygmea

Why this answer is correct

The correct answer is - Zamia pygmea

Key Points

  • Zamia pygmea
  • It is considered the smallest gymnosperm in terms of size.
  • Zamia pygmea is a member of the cycadophyta group, a division of gymnosperms characterized by palm-like leaves.
  • This species typically grows to a height of only 2–3 cm, making it unique among gymnosperms.
  • Gymnosperms
  • These are a group of seed-producing plants that do not produce flowers or fruits.
  • They have naked seeds that are not enclosed in an ovary.
  • Examples include Zamia, Cycas, Gnetum, and Ephedra.

Additional Information

  • Classification of Gymnosperms
  • Gymnosperms are divided into four major groups:
  • Cycadophyta: Includes species like Zamia and Cycas.
  • Coniferophyta: Includes conifers like Pine, Cedar, and Redwood.
  • Gnetophyta: Includes species like Gnetum and Ephedra.
  • Ginkgophyta: Includes the Ginkgo biloba, the only living species in this group.
  • Other Examples of Gymnosperms
  • Gnetum ula: A climbing gymnosperm found in the tropics.
  • Ephedra viridis: A shrub-like gymnosperm native to arid regions.
  • Significance of Gymnosperms
  • They are important for ecological balance as they provide habitats and food for various organisms.
  • They are used in medicinal and economic applications, such as timber production and extraction of ephedrine.

Question 140

Bulbous appendages are found on the cleistothecium of

  1. AOption (a)

    Erysiphe

  2. BOption (b)

    Phyllactinia

  3. COption (c)

    Uncinula

  4. DOption (d)

    Sphaerotheca

View answer & explanation

Correct answer

Answer: (b)B.

Phyllactinia

Why this answer is correct

The correct answer is - Phyllactinia

Key Points

  • Phyllactinia
  • The genus Phyllactinia belongs to the family Erysiphaceae, which are known for causing powdery mildew diseases.
  • The cleistothecium (the closed fruiting body) of Phyllactinia is characterized by having straight, needle-like appendages with a distinct bulbous base.
  • These bulbous bases function as a mechanism for dispersal; as they dry, they cause the cleistothecium to be lifted and released from the host surface.

Additional Information

  • Appendage Morphology in Erysiphales
  • The classification of powdery mildew fungi is traditionally based on the type of appendages found on the cleistothecium.
  • Erysiphe: Has mycelioid appendages which are simple, brown, and resemble regular fungal hyphae.
  • Uncinula: Known for appendages that have hooked or circinate tips (curled like a shepherd's crook).
  • Sphaerotheca: Features mycelioid appendages similar to Erysiphe, but is distinguished by having only one ascus within the cleistothecium.
  • Microsphaera: Features appendages that are dichotomously branched at the tips.
  • Cleistothecium
  • It is a completely closed, spherical ascocarp (fruiting body) that lacks a pre-formed opening or ostiole.
  • The asci inside are released only when the wall of the cleistothecium decays or ruptures.

Question 141

Heterocysts are terminal in position in

  1. AOption (a)

    Gloeotrichia

  2. BOption (b)

    Nostoc

  3. COption (c)

    Oscillatoria

  4. DOption (d)

    Anabaena

View answer & explanation

Correct answer

Answer: (a)A.

Gloeotrichia

Why this answer is correct

The correct answer is - Gloeotrichia

Key Points

  • Gloeotrichia
  • In Gloeotrichia, the filaments are typically tapered, and a single heterocyst is situated at the terminal (basal) position of the filament.
  • Heterocysts are specialized, pale-colored, thick-walled cells found in certain filamentous cyanobacteria (blue-green algae).
  • Their primary function is nitrogen fixation, converting atmospheric nitrogen into a form usable by the plant, facilitated by the enzyme nitrogenase.

Additional Information

  • Nostoc
  • In Nostoc, heterocysts are mostly intercalary (located between vegetative cells), though they can occasionally be terminal. They occur at regular intervals along the filament.
  • Anabaena
  • In Anabaena, heterocysts are primarily intercalary. They are interspersed among the vegetative cells of the unbranched filaments.
  • Oscillatoria
  • Oscillatoria is a genus of filamentous cyanobacteria that does not possess heterocysts. They reproduce by fragmentation through the formation of hormogonia.
  • Function of Heterocysts
  • Heterocysts create an anaerobic environment necessary for the nitrogenase enzyme to function, as nitrogenase is sensitive to oxygen.
  • They maintain this environment by having a thick cell wall that limits oxygen diffusion and by lacking Photosystem II, which produces oxygen during photosynthesis.

Question 142

Example of heterotrichous algae is

  1. AOption (a)

    Cephaleuros

  2. BOption (b)

    Hydrodictyon

  3. COption (c)

    Cladophora

  4. DOption (d)

    Fritschiella

View answer & explanation

Correct answer

Answer: (a)A.

Cephaleuros

Why this answer is correct

The correct answer is - Cephaleuros

Key Points

  • Heterotrichous algae
  • Heterotrichy refers to the presence of two distinct types of filaments or structures in algae: one being prostrate (horizontal) and the other erect (vertical).
  • Cephaleuros is an example of heterotrichous algae due to its differentiated growth patterns in both horizontal and vertical axes.
  • It is a genus of green algae commonly found as epiphytes on leaves and stems, particularly in tropical climates.
  • Other examples of heterotrichous algae
  • Fritschiella: Another heterotrichous algae with a complex body structure.

Additional Information

  • Algae classification
  • Algae are classified based on their structure, pigmentation, and mode of reproduction.
  • Heterotrichous algae exhibit structural differentiation, aiding in adaptation to different habitats.
  • Ecological significance of Cephaleuros
  • Cephaleuros is known as the "red rust" algae because it can cause damage to crops like tea, coffee, and guava.
  • It forms a symbiotic association with plants, but in some cases, it acts as a pathogen.

Question 143

Example of homosporous fern is

  1. AOption (a)

    Adiantum

  2. BOption (b)

    Azolla

  3. COption (c)

    Salvinia

  4. DOption (d)

    Marsilea

View answer & explanation

Correct answer

Answer: (a)A.

Adiantum

Why this answer is correct

The correct answer is - Adiantum

Key Points

  • Homosporous Ferns
  • Adiantum (commonly known as the Maidenhair fern) is a homosporous fern, meaning it produces only one type of spore.
  • All the spores produced by the sporophyte are morphologically similar in size and shape.
  • These spores germinate to give rise to bisexual gametophytes (prothallus) that bear both antheridia (male organs) and archegonia (female organs).

Additional Information

  • Heterospory
  • Heterospory is the production of two distinct types of spores: microspores (which develop into male gametophytes) and megaspores (which develop into female gametophytes).
  • Genera like Salvinia, Azolla, and Marsilea are classic examples of heterosporous ferns.
  • Heterospory is considered a significant evolutionary precursor to the seed habit in gymnosperms and angiosperms.
  • Diversity in Pteridophytes
  • The majority of pteridophytes are homosporous (e.g., Dryopteris, Pteris, and Equisetum).
  • Azolla is a small aquatic fern often used as a biofertilizer due to its symbiotic relationship with nitrogen-fixing cyanobacteria.
  • Salvinia and Marsilea are also aquatic or semi-aquatic ferns that exhibit specialized spore-bearing structures called sporocarps.

Question 144

Antherozoids of Funaria are

  1. AOption (a)

    Non-ciliated

  2. BOption (b)

    Monociliated

  3. COption (c)

    Biciliated

  4. DOption (d)

    Multiciliated

View answer & explanation

Correct answer

Answer: (c)C.

Biciliated

Why this answer is correct

The correct answer is - Biciliated

Key Points

  • Antherozoids in Funaria
  • Antherozoids are the male gametes of Funaria, a type of moss.
  • They are biciliated, meaning they possess two cilia (flagella) for motility.
  • These cilia help the antherozoids swim through water to reach the archegonia (female reproductive structures) for fertilization.
  • Reproductive Mechanism
  • Funaria relies on water for the movement of its motile male gametes.
  • During fertilization, the biciliated antherozoids move towards the egg cell in the archegonia.

Additional Information

  • Characteristics of Funaria
  • Funaria belongs to the class Bryopsida, which includes mosses.
  • It has a life cycle dominated by the gametophyte stage, which is haploid.
  • The sporophyte generation is dependent on the gametophyte for nutrition.
  • Structure of Antheridia
  • Antheridia are the male reproductive structures that produce antherozoids in Funaria.
  • They are multicellular and contain numerous biciliated antherozoids.
  • The release of antherozoids is triggered by the presence of water, facilitating fertilization.
  • Significance of Biciliated Antherozoids
  • Biciliated antherozoids are a key adaptation for aquatic fertilization in mosses like Funaria.
  • This ensures successful reproduction in moist environments, where water acts as a medium for gamete transfer.

Question 145

Prothallus of fern is

  1. AOption (a)

    Kidney shaped

  2. BOption (b)

     Heart shaped

  3. COption (c)

    Club shaped

  4. DOption (d)

    Flask shaped

View answer & explanation

Correct answer

Answer: (b)B.

 Heart shaped

Why this answer is correct

The correct answer is - Heart shaped

Key Points

  • Prothallus of Fern
  • The prothallus is the gametophyte stage in the life cycle of a fern.
  • It is characteristically heart-shaped (cordate), small, and inconspicuous.
  • It is a multicellular, green, and photosynthetic structure that is independent of the sporophyte.
  • It develops from the germination of a haploid spore.

Additional Information

  • Reproductive Organs
  • The prothallus bears both male and female reproductive organs: antheridia and archegonia.
  • Since it produces both types of gametes, it is typically monoecious.
  • Fertilization requires water, as the flagellated male gametes (sperms) must swim to reach the archegonia.
  • Life Cycle Context
  • Ferns follow an alternation of generations where the sporophyte (the main plant body) is diploid (2n) and the gametophyte (prothallus) is haploid (n).
  • The sporophyte is the dominant phase in the life cycle of pteridophytes like ferns.
  • Rhizoids
  • The prothallus is attached to the soil by unicellular rhizoids, which help in the absorption of water and minerals.

Question 146

Which of the following is a bryophyte ?

  1. AOption (a)

    Bog Moss

  2. BOption (b)

    Reindeer Moss

  3. COption (c)

    Club Moss

  4. DOption (d)

    Iris Moss

View answer & explanation

Correct answer

Answer: (a)A.

Bog Moss

Why this answer is correct

The correct answer is - Bog Moss

Key Points

  • Bog Moss (Sphagnum)
  • Sphagnum, commonly known as Bog Moss or Peat Moss, is a member of the division Bryophyta.
  • Bryophytes are known as the amphibians of the plant kingdom because they live in soil but depend on water for sexual reproduction.
  • Sphagnum is economically important as it provides peat, which is used as fuel and as packing material for trans-shipment of living materials due to its water-holding capacity.

Additional Information

  • Reindeer Moss
  • Despite its name, it is not a moss but a Lichen (Cladonia rangiferina).
  • It is a primary food source for reindeer and caribou in arctic and subarctic regions.
  • Club Moss
  • This is a Pteridophyte (Lycopodium), which is a primitive vascular plant.
  • Unlike bryophytes, they possess vascular tissues (xylem and phloem) and have a dominant sporophyte phase.
  • Iris Moss (Irish Moss)
  • Also known as Chondrus crispus, it is a species of Red Algae (Rhodophyta).
  • It is commonly used in the food industry to produce carrageenan, a thickening agent.
  • Bryophytes Classification
  • Bryophytes are broadly classified into Liverworts (Hepaticopsida), Hornworts (Anthocerotopsida), and Mosses (Bryopsida).
  • They lack true roots, stems, or leaves but possess root-like structures called rhizoids.

Question 147

Cyanobacteria growing in green light would appear

  1. AOption (a)

    Green

  2. BOption (b)

    Blue

  3. COption (c)

    Red

  4. DOption (d)

    White

View answer & explanation

Correct answer

Answer: (c)C.

Red

Why this answer is correct

The correct answer is - Red

Key Points

  • Chromatic Adaptation (Gaidukov Effect)
  • Certain cyanobacteria (blue-green algae) possess the ability to change their color based on the wavelength of light available in their environment, a phenomenon called complementary chromatic adaptation or the Gaidukov effect.
  • When cyanobacteria are grown in green light, they selectively synthesize a higher concentration of phycoerythrin.
  • Phycoerythrin is a red pigment that specifically absorbs green light for photosynthesis.
  • As a result of accumulating this red pigment to maximize light absorption, the cyanobacteria appear red in color.

Additional Information

  • Phycobiliproteins
  • Cyanobacteria use phycobilisomes as light-harvesting complexes, which contain pigments known as phycobiliproteins.
  • The two primary phycobiliproteins involved in chromatic adaptation are Phycocyanin (which appears blue and absorbs orange-red light) and Phycoerythrin (which appears red and absorbs green light).
  • Adaptation to Light Quality
  • If the same cyanobacteria are shifted to red light, they will decrease phycoerythrin production and increase phycocyanin production, making them appear blue-green.
  • This physiological adjustment ensures maximum photosynthetic efficiency under varying light conditions, such as different depths in a water body.

Question 148

Red colour of red sea is due to presence of

  1. AOption (a)

    Sargassam

  2. BOption (b)

    Laminaria

  3. COption (c)

    Ulva

  4. DOption (d)

    Trichodesmium

View answer & explanation

Correct answer

Answer: (d)D.

Trichodesmium

Why this answer is correct

The correct answer is - Trichodesmium

Key Points

  • Trichodesmium erythraeum
  • The red colour of the Red Sea is due to the presence of a cyanobacterium (blue-green algae) called Trichodesmium erythraeum.
  • This microscopic algae contains a red pigment called phycoerythrin.
  • When these organisms undergo massive multiplication (blooms), they die off and release the pigment, giving the water a reddish-brown appearance.

Additional Information

  • Cyanobacteria
  • Cyanobacteria are prokaryotic organisms that perform oxygenic photosynthesis.
  • They are often referred to as blue-green algae, though they are technically bacteria.
  • Many species, including Trichodesmium, are capable of nitrogen fixation, converting atmospheric nitrogen into a form usable by other marine life.
  • Other Algae mentioned
  • Sargassum: A genus of brown algae (Phaeophyceae) that often floats in large masses in the ocean (Sargasso Sea).
  • Laminaria: Also known as kelp, it is a type of brown algae used as food and a source of iodine.
  • Ulva: Commonly known as sea lettuce, it is a genus of green algae (Chlorophyceae).
  • Pigmentation in Algae
  • Chlorophyceae (Green algae) contain chlorophyll a and b.
  • Phaeophyceae (Brown algae) contain fucoxanthin.
  • Rhodophyceae (Red algae) contain phycoerythrin.

Question 149

Source of CO2 for photosynthesis during day in CAM plants is

  1. AOption (a)

    3-PGA

  2. BOption (b)

    Maleic acid

  3. COption (c)

    Oxalo-acetic acid

  4. DOption (d)

    Pyruvate

View answer & explanation

Correct answer

Answer: (a)A.

3-PGA

Why this answer is correct

The correct answer is - 3-PGA

Key Points

  • CAM plants
  • Crassulacean Acid Metabolism (CAM) plants are adapted to arid conditions where water conservation is crucial.
  • They open their stomata at night to fix CO2 into 4-carbon organic acids and close them during the day to minimize water loss.
  • Source of CO2 during the day
  • During the day, 3-PGA (3-phosphoglyceric acid) is formed as an intermediate in the Calvin cycle.
  • The CO2 required for photosynthesis is released from organic acids such as malic acid that were stored during the night.
  • Role of 3-PGA
  • 3-PGA acts as the first stable intermediate in the Calvin cycle, which occurs in the chloroplasts during the day.
  • It is involved in the process of carbon fixation, leading to the synthesis of glucose and other carbohydrates.

Additional Information

  • CAM cycle phases
  • Night phase: CO2 is fixed into oxaloacetic acid (OAA), which is converted into malic acid and stored in vacuoles.
  • Day phase: Malic acid is decarboxylated to release CO2, which is then used in the Calvin cycle for photosynthesis.
  • Key organic intermediates
  • Oxaloacetic acid (OAA): A 4-carbon compound formed during the initial fixation of CO2.
  • Malic acid: Stores CO2 in the vacuole and releases it for photosynthesis during the day.
  • Pyruvate: Formed during decarboxylation of malic acid and recycled in metabolic processes.
  • Adaptations of CAM plants
  • Examples include cacti, succulents, and pineapple, which thrive in desert-like conditions.
  • They exhibit anatomical adaptations like thick leaves with reduced surface area and sunken stomata to minimize water loss.

Question 150

Which of the following amino acid usually accumulates during drought?

  1. AOption (a)

    Glutamine

  2. BOption (b)

    Proline

  3. COption (c)

    Asparate

  4. DOption (d)

    Tyrosine

View answer & explanation

Correct answer

Answer: (b)B.

Proline

Why this answer is correct

The correct answer is - Proline

Key Points

  • Proline
  • Proline is an amino acid that significantly accumulates in many plant species in response to environmental stresses such as drought, salinity, and extreme temperatures.
  • It functions as an osmoprotectant (compatible solute), which helps the plant maintain its osmotic balance and cellular turgor without interfering with normal metabolism.
  • The accumulation of proline helps in membrane stabilization and protects proteins from denaturation during water deficit conditions.

Additional Information

  • Drought Resistance Mechanisms
  • Plants have evolved various mechanisms to survive drought, including drought avoidance (deep roots) and drought tolerance (osmotic adjustment).
  • Osmotic adjustment involves the accumulation of solutes like proline, glycine betaine, and soluble sugars to lower the water potential of the cell.
  • Role of Proline as an Antioxidant
  • Beyond its role as an osmolyte, proline acts as a scavenger of reactive oxygen species (ROS), protecting the cell from oxidative stress triggered by drought.
  • It also serves as a sink for excess reducing power and a source of nitrogen and carbon for quick recovery after the stress period ends.
  • Biosynthesis
  • In plants, proline is synthesized mainly from glutamate through the action of the enzyme pyrroline-5-carboxylate synthetase (P5CS).
  • Under drought stress, the expression of genes encoding these enzymes is upregulated, leading to high levels of proline accumulation.

150 questions in the full paper