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The correct answer is All I, II and III are correct.

Key Points

• The term Formula Unit Mass is specifically employed for substances whose constituent particles are ions. Unlike covalent compounds which consist of discrete molecules, ionic compounds exist as a continuous three-dimensional crystal lattice. Hence, statement I is correct.
• The Formula Unit Mass is defined as the sum of the atomic masses of all atoms present in the empirical formula or the formula unit of an ionic compound. It represents the mass of the simplest ratio of ions in the substance. Hence, statement II is correct.
• For Sodium Chloride (NaCl), the calculation involves adding the atomic mass of Sodium (Na), which is 23 u, and the atomic mass of Chlorine (Cl), which is 35.5 u. The resulting sum is 23 + 35.5 = 58.5 u. Hence, statement III is correct.

 Additional Information

• Molecular Mass:
• This term is used exclusively for covalent molecules like water (H₂O) or methane (CH₄).
• It is the sum of the atomic masses of all atoms in a single molecule of the substance.
• Ionic Compounds:
• These are formed by the transfer of electrons between metals and non-metals.
• The structure is held together by strong electrostatic forces of attraction.
• Atomic Mass Unit (u):
• Formerly known as amu, it is the standard unit used to express atomic and molecular weights.
• It is defined as 1/12^th of the mass of an atom of Carbon-12.

The correct answer is Budding.

Key Points

• Hydra is a freshwater organism belonging to the phylum Cnidaria, known for its remarkable biological processes and regenerative abilities.
• Budding is a specific form of asexual reproduction where a new individual originates from a specialized generative anatomical point on the parent organism.
• In Hydra, the process is initiated by repeated mitotic cell divisions at a specific site, leading to the formation of a small protrusion or outgrowth known as a bud.
• As the bud matures, it develops essential structures such as tentacles and a mouth while remaining physically attached to the parent, receiving nutrients through the parent's gastrovascular cavity.
• Upon reaching a certain level of maturity and size, the new Hydra constricts at the base, detaches from the parent body, and begins life as an independent, genetically identical clone.

 Additional Information

• Sexual reproduction:
• Involves the production and fusion of haploid gametes (sperm and eggs) to create a diploid zygote.
• In Hydra, this typically occurs under unfavorable environmental conditions to ensure genetic diversity and survival.
• Regeneration:
• The process of renewing or restoring lost or damaged tissues, organs, or entire body parts.
• While Hydra exhibits extreme morphallaxis (reorganization of existing tissues), regeneration is generally a repair mechanism rather than a primary planned reproductive strategy like budding.
• Parthenogenesis:
• A type of asexual reproduction where an embryo develops from an unfertilized egg cell.
• This phenomenon is observed in various invertebrates (like rotifers and bees) and some vertebrates, but it is not the mechanism used by Hydra for forming body protrusions.

The correct answer is They recycle nutrients by breaking down dead organisms into simple substances.

Key Points

• Decomposers, primarily consisting of bacteria and fungi, are heterotrophic organisms that break down complex organic matter from dead plants and animals into simpler inorganic forms.
• They perform the critical function of nutrient cycling by releasing essential elements like Nitrogen, Phosphorus, and Potassium back into the soil, which are then reused by primary producers.
• The process of decomposition involves several stages, including fragmentation, leaching, catabolism, humification, and mineralization, facilitated by extracellular enzymes secreted by these organisms.
• By digesting detritus (dead organic matter), decomposers act as the natural scavengers of the ecosystem, preventing the accumulation of waste and maintaining the ecological balance.
• They represent the final link in the Detritus Food Chain (DFC), ensuring that the flow of matter in an ecosystem remains cyclic rather than linear.

 Additional Information

• Autotrophs (Producers):
• These organisms, primarily green plants and algae, perform Photosynthesis.
• They use chlorophyll to trap solar energy and convert inorganic substances like carbon dioxide and water into energy-rich organic compounds (glucose). This relates to the incorrect options describing energy production from sunlight.
• Saprotrophs:
• This term specifically refers to decomposers that feed by absorbing nutrients from decaying matter through osmophagy.
• Unlike Detritivores (e.g., earthworms), which ingest and fragment waste internally, saprotrophs break down matter externally.
• Trophic Levels:
• In a Grazing Food Chain, energy moves from producers to herbivores and then to carnivores. Decomposers bridge the gap between all levels by processing the remains of every organism once they die.

The correct answer is 1200 W.

Key Points

• Resistance (R) is defined as the property of a conductor that opposes the flow of electric current. In the given problem, the resistance of the device is specified as 75 Ω.
• Electric Current (I) is the rate of flow of electric charge through a cross-section of a conductor. The device carries a steady current of 4 A.
• The Electric Power (P) dissipated by a resistive component is the rate at which electrical energy is converted into heat energy.
• The relationship between power, current, and resistance is given by the formula: P = I² × R. This is derived from Ohm's Law and the basic power formula P = V × I.
• To find the power dissipated, we substitute the given values into the formula: P = (4 A)² × 75 Ω.
• First, calculate the square of the current: 4² = 16.
• Then, multiply the result by the resistance: 16 × 75 = 1200.
• The resulting value for the power dissipated is 1200 Watts (W).

 Additional Information

• Ohm's Law:
• States that V = I × R, where V is potential difference, I is current, and R is resistance.
• By substituting V/R for I or I × R for V in the power formula, we obtain alternative expressions: P = V² / R and P = V × I.
• Unit of Power:
• The SI unit of power is the Watt (W), named after the Scottish inventor James Watt.
• One Watt is defined as the consumption of energy at the rate of one Joule per second (1 J/s).
• Joule's Law of Heating:
• Describes the heat produced in a resistor as H = I² × R × t, where t is the time for which current flows.
• This principle is utilized in electric heaters, irons, and toasters.

The correct answer is The force of attraction of the earth.

Key Points

• According to Newton's First Law of Motion, an object will continue in a straight line unless acted upon by an external force. For the Moon to move in a nearly circular orbit around the Earth, its direction of motion must constantly change, which requires a centripetal force directed toward the center of the circle.
• The gravitational force of attraction between the Earth and the Moon provides this necessary centripetal force. Without this force, the Moon would fly off in a tangential straight-line path due to its inertia.
• This interaction is governed by Newton's Universal Law of Gravitation, which states that every particle in the universe attracts every other particle with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.
• The magnitude of the gravitational force (F) is calculated using the formula F = G × M × m / r², where G is the Gravitational Constant, M is the mass of the Earth, m is the mass of the Moon, and r is the distance between them.

 Additional Information

• Centripetal Force:
• It is not a new kind of force but a role played by existing forces like gravity, tension, or friction.
• For an object of mass m moving at velocity v in a radius r, it is expressed as F = mv² / r.
• Inertia:
• Inertia is the inherent property of matter by which it resists any change in its state of rest or uniform motion.
• In the Moon's orbit, inertia explains why the Moon wants to move forward, while gravity pulls it inward, resulting in a curved path.
• Internal Forces:
• These are forces exerted by particles of a system on each other. According to Newton's Third Law, they occur in equal and opposite pairs and cannot change the motion of the center of mass of the system.

The correct answer is Flower types and their abundance for nectar gathering.

Key Points

• The quality, taste, and medicinal value of honey are primarily determined by the pasturage, which refers to the flora or flowering plants available to the bees for foraging.
• Nectar is the sugary fluid secreted by flowers that bees collect and convert into honey through enzymatic activity and moisture evaporation within the hive.
• The abundance of flowers in the vicinity of the apiary directly influences the quantity of honey produced, as it determines how much raw material worker bees can gather during their foraging flights.
• Different flower types impart distinct characteristics such as aroma, color, and viscosity to the honey; for example, honey from Litchi, Neem, or Sunflower plantations has unique therapeutic properties and flavors.
• The availability of pollen alongside nectar is also crucial, as pollen serves as the primary protein source for the growth and development of the bee colony.

 Additional Information

• Common Bee Varieties used in Apiculture:
• Apis mellifera: Also known as the Italian bee, it is widely used for commercial honey production due to its high honey-collection capacity and docile nature.
• Apis cerana indica: The Indian bee, commonly used in traditional beekeeping across the subcontinent.
• Apis dorsata: The Rock bee, known for being aggressive and producing large quantities of honey in the wild.
• Apis florea: The Little bee, which builds small, open combs and produces lower yields.
• Factors affecting Hive Management:
• While temperature and beehive size influence the health of the colony and storage efficiency, they do not define the organoleptic properties (taste and smell) of the honey itself.
• The worker bees are the ones responsible for foraging, and their efficiency is maximized when the foraging range contains a diverse and dense floral carpet.

The correct answer is Deoxygenated blood is pumped from the right ventricle to the lungs..

Key Points

• Oxygenated blood travels from the lungs to the Left Atrium via the Pulmonary Veins, while the right atrium receives deoxygenated blood from the body. Hence, statement 1 is incorrect.
• The Left Ventricle is the strongest chamber of the heart, pumping oxygenated blood into the Systemic Circulation through the Aorta to supply the body's tissues. Hence, statement 2 is incorrect.
• Purification, or the exchange of gases, occurs within the Lungs; therefore, the blood sent from the heart to the lungs must be deoxygenated (depleted of oxygen) to be refreshed. Hence, statement 3 is incorrect.
• In the Pulmonary Circuit, the Right Ventricle contracts to eject deoxygenated blood into the Pulmonary Artery, which carries it directly to the Lungs for oxygenation. Hence, statement 4 is correct.

 Additional Information

• Pulmonary Artery and Veins:
• The Pulmonary Artery is unique as it is the only artery in the adult human body that carries Deoxygenated Blood.
• The Pulmonary Veins are the only veins that carry Oxygenated Blood, transporting it from the lungs to the Left Atrium.
• Heart Valves:
• The Pulmonary Valve prevents the backflow of blood from the pulmonary artery into the Right Ventricle.
• The Tricuspid Valve regulates blood flow between the Right Atrium and the Right Ventricle.
• Gaseous Exchange:
• This occurs at the Alveoli where CO₂ diffuses out of the blood and O₂ diffuses into the Red Blood Cells to bind with Hemoglobin.
• Double Circulation:
• Humans have a Four-Chambered Heart that ensures complete separation of oxygenated and deoxygenated blood, allowing for efficient Metabolic Activity.

The correct answer is They always contain carbon.

Key Points

• Organic compounds are a vast class of chemical substances characterized by the presence of carbon atoms covalently bonded to other elements. The study of these molecules is the core of organic chemistry.
• The tetravalency of carbon enables it to form four covalent bonds, allowing for the creation of stable and complex molecular architectures including linear chains, branched structures, and aromatic rings.
• Carbon possesses the unique property of catenation, which is the ability of an element to form long-chain polymers or rings by bonding with atoms of the same element. This is why millions of organic compounds exist.
• While hydrogen is present in the vast majority of organic compounds (forming hydrocarbons), the presence of carbon is the sole universal requirement. Even compounds like carbon tetrachloride (CCl₄) are considered organic despite lacking hydrogen.
• The distinction between organic and inorganic was historically based on the Vital Force Theory, but since Friedrich Wohler synthesized urea in 1828, the definition has shifted strictly to the carbon-centric chemical composition.

 Additional Information

• Bonding Nature:
• Organic compounds predominantly feature covalent bonds. Ionic bonds are typical of inorganic salts like Sodium Chloride (NaCl), where electrons are transferred rather than shared.
• Heteroatoms:
• Oxygen and Nitrogen are common in organic functional groups like alcohols (−OH), carboxylic acids (−COOH), and amines (−NH₂).
• However, they are not present in hydrocarbons such as Methane (CH₄), Propane (C₃H₈), or Benzene (C₆H₆), meaning they are not a universal characteristic of all organic substances.
• Exceptions:
• Simple carbon-containing compounds like carbonates, cyanides, and carbon oxides (e.g., CO₂) are traditionally classified as inorganic due to their properties and historical context.

The correct answer is 2 m/s.

Key Points

• Average Speed is defined as the total distance traveled by an object divided by the total time taken to cover that distance.
• In this scenario, the body moves from point A to point B, covering a straight-line distance of 10 meters.
• The body then travels back from point B to point A along the same path, covering the same distance of 10 meters again.
• The Total Distance covered for the entire journey is calculated as: 10 m + 10 m = 20 meters.
• The time taken for the first leg is 5 seconds, and the time for the return leg is also 5 seconds. Thus, the Total Time taken is: 5 s + 5 s = 10 seconds.
• Applying the formula for speed: Average Speed = Total Distance ÷ Total Time. Substituting the values gives: 20 m ÷ 10 s = 2 m/s.

 Additional Information

• Average Velocity vs. Speed:
• While Average Speed is a scalar quantity (only magnitude), Average Velocity is a vector quantity (magnitude and direction).
• Because the body returns to its starting point, the net displacement is 0 meters. Therefore, the average velocity for this journey is 0 m/s.
• SI Units:
• The International System of Units (SI), established in 1960, identifies meters per second (m/s) as the standard unit for speed and velocity.
• To convert m/s to km/h, the value is multiplied by 3.6; thus, 2 m/s is equivalent to 7.2 km/h.
• Uniform Motion:
• If an object covers equal distances in equal intervals of time, it is in uniform motion. Here, the speed is constant at 2 m/s for both halves of the trip.

The correct answer is Aluminium.

Key Points

• Amphoteric oxides are defined as metallic oxides that can react with both acids and bases to produce salt and water, thereby demonstrating both acidic and basic characteristics.
• When Aluminium (Al) is exposed to air, it reacts with oxygen to form a thin, stable protective layer of Aluminium Oxide (\( Al_{2}O_{3} \)) on its surface.
• The basic nature of \( Al_{2}O_{3} \) is demonstrated when it reacts with Hydrochloric acid (HCl) to form Aluminium chloride: \( Al_{2}O_{3} + 6HCl \rightarrow 2AlCl_{3} + 3H_{2}O \).
• The acidic nature of \( Al_{2}O_{3} \) is demonstrated through its reaction with a strong base like Sodium hydroxide (NaOH) to form Sodium aluminate: \( Al_{2}O_{3} + 2NaOH \rightarrow 2NaAlO_{2} + H_{2}O \).

 Additional Information

• Basic Oxides:
• Sodium (Na) and Potassium (K) are highly reactive alkali metals that form Sodium Oxide (\( Na_{2}O \)) and Potassium Oxide (\( K_{2}O \)), which are strictly basic and react with water to form strong alkalis.
• Calcium (Ca) reacts with oxygen to form Calcium Oxide (CaO), commonly known as Quicklime, which is a basic oxide and turns red litmus blue when dissolved in water.
• Other Amphoteric Examples:
• Beyond Aluminium, other metals that form amphoteric oxides include Zinc (ZnO), Lead (PbO), and Tin (SnO).
• These oxides are crucial in industrial chemistry, particularly in the manufacturing of glass, ceramics, and as catalysts in organic synthesis.