Search Previous Year Questions

The correct answer is Vitamin B

Concept:

• Vitamins are the essential nutrients that the body needs to function, grow and develop.
• The term vitamin was coined by Casimir Funk.
• Vitamin is the nutrient which is also known as co-enzyme.
• As the body does not produce vitamins itself, it must be acquired through the food we eat or in some cases through supplements.
• There are 13 vitamins - A, C, D, E, K, and B vitamins (thiamine, riboflavin, niacin, pantothenic acid, biotin, B6, B12, and folate), each of them have a different job.

Explanation:

• Vitamin A, D, E, K are fat-soluble vitamins and are stored in fat cells.
• Vitamin B and C are water-soluble vitamins that are not stored in your body.

Additional Information 

The correct answer is Multiple ovulation embryo transfer technology 

Explanation:

• MOET stands for multiple ovulation embryo transfer.
• It is a technology in which multiple eggs are fertilized in an animal after artificial insemination.
• This method is used in cattle breeding procedures to obtain desirable characteristics.
• In MOET, cows are injected with FSH (follicle stimulating hormone) like activity to induce maturation of follicles and superovulation.
• Superovulation helps in the formation of about 6 to 8 cells in a single cycle.
• After artificial insemination, embryos are collected at the 8 to 32 cells stage.
• These embryos are then transferred to the surrogate mother.
• These progenies obtained will now have the desirable trait.

The correct answer is Dog

Explanation:

• Several cyclical changes in the activities of ovaries, accessory ducts, hormones occur during the reproductive phase in the females of placental mammals.
• Such changes in the non-primates like cows, sheep, dogs etc., is called the Oestrus cycle.
• In primates like monkeys, humans, apes, it is called the Menstrual cycle.
• In the Oestrus cycle, the endometrium is reabsorbed into the body whereas in the Menstrual cycle the endometrium is shed off in each cycle.

The correct answer is Ecological succession

Explanation:

The sequence of communities that successively change in an area is referred to as ecological succession. Ecological succession is the process by which the structure of a biological community evolves over time. There are two main types: primary and secondary succession.

Primary Succession:

• Occurs in an area where there were previously no living organisms and the soil had not yet formed, such as after a lava flow or on a new island created by volcanic activity.
• The initial species that colonize such areas are called pioneer species. These species are typically hardy and capable of withstanding harsh conditions. An example of pioneer species are lichens and certain types of algae.
• Over time, these pioneer species alter the environment (e.g., by breaking down rock into soil), making it more habitable for other species to move in and establish themselves.

Secondary Succession:

• Occurs in areas where a community previously existed but has been disturbed or removed by events like fires, floods, or human activities, leaving the soil intact.
• Because the soil is already present, secondary succession usually proceeds faster than primary succession.
• The first plants to grow back might be fast-growing grasses and weeds which are then followed by more complex plants like shrubs and young trees.

​A sere refers to a series of stages or communities that follow one another in a specific sequence during ecological succession, from the initial colonization to the climax community. Each stage within this progression is known as a seral stage. For example, in the succession of a forest, the sere might include the stages from pioneer species to intermediate species to a mature forest community.

• The community that is in near equilibrium with the environment is called a climax community.
• The species that invade a bare area are called pioneer species. 
• Lichens are the pioneer species on a bare area or Xerarch condition.
• Phytoplanktons are the pioneer species in Hydrarch succession.

The correct answer is Epidermis → Endothecium → Middle layers → Tapetum

Concept:

• A typical angiosperm anther is bilobed with each lobe having two theca, i.e., they are dithecous
• Often a longitudinal groove runs lengthwise separating the theca
• The bilobed nature of an anther is very distinct in the transverse section of the anther.
• The anther is a four-sided (tetragonal) structure consisting of four microsporangia located at the corners, two in each lobe

Explanation:

Structure of microsporangium:

• In a transverse section, a typical microsporangium appears near circular in outline.
• It is generally surrounded by four wall layers the epidermis, endothecium, middle layers and the tapetum.
• The outer three wall layers perform the function of protection and help in dehiscence of anther to release the pollen.
• The innermost wall layer is the tapetum. It nourishes the developing pollen grains.
• Cells of the tapetum possess dense cytoplasm and generally have more than one nucleus.

The correct answer is Goiter

Explanation:

• The thyroid gland is a vital hormone gland that plays a major role in the metabolism, growth, and development of the human body. It helps to regulate many body functions by releasing a steady amount of thyroid hormones into the bloodstream.

• Thyroxine (T4) is one of the hormones produced by the thyroid gland. It is responsible for regulating metabolism, heart and digestive functions, muscle control, brain development, and bone maintenance.

• Iodine is an essential nutrient that is crucial for the production of thyroxine. A deficiency in iodine can lead to thyroid gland problems, including goiter and hypothyroidism.

The correct answer is AI

Explanation:

• Artificial Insemination (AI) is a method of assisted reproduction that involves the direct insertion of sperm into a woman's reproductive tract.
• In this technique, the semen collected either from the husband or a healthy donor is artificially introduced either into the vagina or into the uterus (IUI – intra-uterine insemination) of the female.
• The purpose of AI is to facilitate fertilization when natural conception is not possible or has proven difficult.

Other Options:

• IUT (Intrauterine Transfer): The zygote or early embryos (with upto 8 blastomeres) could then be transferred into the fallopian tube (ZIFT–zygote intra-fallopian transfer) and embryos with more than 8 blastomeres, into the uterus (IUT – intra-uterine transfer),
• ICSI (Intracytoplasmic Sperm Injection): This is a technique used in conjunction with IVF (In Vitro Fertilization) where a single sperm is injected directly into an egg to facilitate fertilization. This method is commonly used for severe male infertility issues.
• GIFT (Gamete Intrafallopian Transfer): This procedure involves placing eggs and sperm directly into the fallopian tubes so that fertilization occurs naturally within the woman's body.

The correct answer is Alec Jeffreys

Explanation:

• DNA fingerprinting was developed by Alec Jeffreys in 1984.
• It is based on DNA polymorphism.
• Humans are almost 99.9% identical and the rest 0.1% constitutes about 3 million differences in our genome.
• DNA polymorphism - These are inheritable mutations that occur at a high frequency in a population.
• Such variations occur frequently in non-coding DNA sequences and keep accumulating over generations.
• These mutations are the basis of variability or polymorphism in a population.
• Satellite DNA shows high degree of polymorphism and hence, was used by Jeffreys for DNA fingerprinting.
• The DNA probes used were VNTRs.
• VNTR- Variable Number of Tandem Repeats or VNTRs are composed of 8-80 bp sequences which are tandemly repeated to form 1-30kb length of DNA.

Procedure:

1. Isolation of DNA
2. Digestion of DNA by restriction endonuclease
3. Separation of DNA fragments by gel electrophoresis
4. Transferring of separated DNA fragments to synthetic membranes like nylon and nitrocellulose - Southern Blotting technique
5. Hybridization by using radio-labelled VNTR probes.
6. Detection of hybridized DNA fragments by autoradiography.

Other Options:

• Thomas Morgan: Thomas Hunt Morgan was an American geneticist and evolutionary biologist who is best known for his work on the role chromosomes play in heredity. He discovered the white-eyed mutation in fruit flies which led to the establishment of the chromosome theory of inheritance.
• Sutton: Walter Sutton was an American geneticist who independently proposed the chromosome theory of inheritance, which states that chromosomes carry the cell's units of inheritance.
• Meselson: Matthew Meselson, along with Franklin Stahl, is known for the Meselson-Stahl experiment which provided evidence for the semi-conservative replication of DNA.

The correct answer is Nucleosome 

Explanation:

• The nucleosome, a section of DNA wrapped around a core of proteins, is the fundamental subunit of chromatin.
• Each nucleosome is comprised of a little less than two turns of DNA wrapped around a set of eight proteins called histones, which are known as a histone octamer.
• The negatively charged DNA is wrapped around the positively charged histone octamer (protein) to form a structure called a nucleosome.
• Each nucleosome is comprised of a little less than two turns of DNA wrapped around a set of eight proteins called histones, which are known as histone octamer.
• Each histone octamer is composed of two copies of each of the histone proteins H2A, H2B, H3, and H4.
• A typical nucleosome contains 200 bp of DNA helix.
• Nucleosomes constitute the repeating unit of a structure in the nucleus called chromatin, threadlike stained (coloured) bodies seen in the nucleus.
• The nucleosomes in chromatin are seen as ‘beads-on-string’ structures when viewed under an electron microscope (EM).

The correct answer is ERV + RV

Concept:

• The respiratory system includes various lung volumes and capacities, which are essential for understanding lung function and diagnosing respiratory conditions.
• Key lung volumes include Tidal Volume (TV), Expiratory Reserve Volume (ERV), Inspiratory Reserve Volume (IRV), and Residual Volume (RV).
• These volumes can be combined to form lung capacities, such as Expiratory Capacity (EC), Total Lung Capacity (TLC), and Functional Residual Capacity (FRC).

Explanation:

• Functional Residual Capacity (FRC): Volume of air that will remain in the lungs after a normal expiration. This includes ERV+RV.
• Inspiratory capacity (IC)  - Total volume of air a person can inspire after a normal expiration. This includes tidal volume and inspiratory reserve volume (TV+IRV).
• Expiratory Capacity (EC): Total volume of air a person can expire after a normal inspiration. This includes tidal volume and expiratory reserve volume (TV+ERV).
• Vital Capacity (VC) - The maximum volume of air a person can breathe in after a forced expiration. This includes ERV, TV and IRV
• Residual Volume (RV) - Volume of air remaining in the lungs even after a forcible expiration. This averages 1100 mL to 1200 mL.
• Tidal Volume (TV) - Volume of air inspired or expired during normal respiration. It is approx. 500 mL., i.e., a healthy man can inspire or expire approximately 6000 to 8000 mL of air per minute.