Q1. Life without air would be:
Correct Answer: (d)
Anaerobic organisms (obligate or facultative) can live and produce energy without the presence of oxygen.
Anaerobic organisms (obligate or facultative) can live and produce energy without the presence of oxygen.
Q2. The given figure shows a typical structure of monocotyledonous seeds. Identify the parts A, B, C, D and E marked in the given figures.
Correct Answer: (c)
In a maize seed: A - Endosperm, B - Embryo, C - Scutellum, D - Coleoptile (covering plumule), E - Coleorhiza (covering radicle).
In a maize seed: A - Endosperm, B - Embryo, C - Scutellum, D - Coleoptile (covering plumule), E - Coleorhiza (covering radicle).
Q3. Arrange the following events into the correct order after a paper cut occurs.
Correct Answer: (b)
The correct sequence is: bacteria enter the cut, injured cells release histamine to initiate inflammation, macrophages engulf invading bacteria, and finally helper T cells are activated to initiate adaptive immunity.
The correct sequence is: bacteria enter the cut, injured cells release histamine to initiate inflammation, macrophages engulf invading bacteria, and finally helper T cells are activated to initiate adaptive immunity.
Q4. Refer the figure of citric acid cycle and choose the correct combination of labelling (P, Q, R, S and T) indicating the number of carbon compounds in the substrate molecules, involved in the given figure.
Correct Answer: (a)
P: OAA (4C). Q: Citrate (6C). R: alpha-ketoglutarate (5C). S: Succinate (4C). T: Malate (4C).
P: OAA (4C). Q: Citrate (6C). R: alpha-ketoglutarate (5C). S: Succinate (4C). T: Malate (4C).
Q5. Gaseous hormone is
Correct Answer: (a)
Ethylene is the only phytohormone that exists as a gas at physiological temperatures, primarily regulating ripening and senescence.
Ethylene is the only phytohormone that exists as a gas at physiological temperatures, primarily regulating ripening and senescence.
Q6. The basic mechanism of DNA replication is semiconservative with two new molecules,
Correct Answer: (c)
Semiconservative replication means that when the DNA double helix is copied, the two parental strands separate. Each original strand then serves as a template for the synthesis of a new complementary strand, resulting in two daughter molecules that each consist of one old and one new strand.
Semiconservative replication means that when the DNA double helix is copied, the two parental strands separate. Each original strand then serves as a template for the synthesis of a new complementary strand, resulting in two daughter molecules that each consist of one old and one new strand.
Q7. The chemiosmotic coupling hypothesis of oxidative phosphorylation proposes that adenosine triphosphate (ATP) is formed because:
Correct Answer: (c)
ATP synthesis is driven by the energy released as protons flow back into the matrix down their electrochemical gradient through ATP synthase.
ATP synthesis is driven by the energy released as protons flow back into the matrix down their electrochemical gradient through ATP synthase.
Q8. In the leaves of C4 plants, malic acid formation during CO2 fixation occurs in the cells of
Correct Answer: (d)
Initial CO2 fixation into C4 acids like malic or aspartic acid takes place in the mesophyll cells of C4 leaves.
Initial CO2 fixation into C4 acids like malic or aspartic acid takes place in the mesophyll cells of C4 leaves.
Q9. A forensic scientist cuts DNA from a crime scene and DNA from a suspect with the same enzyme. Which tool should the scientist use to separate the DNA fragments according to their size?
Correct Answer: (c)
Gel electrophoresis separates fragments of DNA according to their size. Bacterial transformation involves the uptake and expression of foreign DNA by bacteria, so choice (A) is incorrect. CRISPR-Cas9 is used for gene editing, so choice (B) is incorrect. PCR amplifies specific sequences of DNA, so choice (D) is also incorrect.
Gel electrophoresis separates fragments of DNA according to their size. Bacterial transformation involves the uptake and expression of foreign DNA by bacteria, so choice (A) is incorrect. CRISPR-Cas9 is used for gene editing, so choice (B) is incorrect. PCR amplifies specific sequences of DNA, so choice (D) is also incorrect.
Q10. During seed germination, this hormone produces the signal for the aleurone to begin starch breakdown.
Correct Answer: (c)
Gibberellic acid (GA) is synthesized by the embryo and moves to the aleurone layer, where it triggers the production of α-amylase and other enzymes to hydrolyze stored starch.
Gibberellic acid (GA) is synthesized by the embryo and moves to the aleurone layer, where it triggers the production of α-amylase and other enzymes to hydrolyze stored starch.
Q11. Mountain climbers may have difficulty at high elevations because
Correct Answer: (a)
At high altitudes, the total atmospheric pressure is lower. Since oxygen still makes up about 21% of the air, its partial pressure (PO2) also decreases. This reduction in PO2 decreases the pressure gradient necessary to drive oxygen diffusion from the lungs into the blood.
At high altitudes, the total atmospheric pressure is lower. Since oxygen still makes up about 21% of the air, its partial pressure (PO2) also decreases. This reduction in PO2 decreases the pressure gradient necessary to drive oxygen diffusion from the lungs into the blood.
Q12. Morphogenesis is the development of
Correct Answer: (a)
Morphogenesis refers to the biological process that causes an organism to develop its shape. In plants, it specifically describes the development of the growth form through orchestrated cell division and expansion.
Morphogenesis refers to the biological process that causes an organism to develop its shape. In plants, it specifically describes the development of the growth form through orchestrated cell division and expansion.
Q13. Where among the following will you find pitcher plant ?
Correct Answer: (a)
Pitcher plants (Nepenthes) are found in the humid tropical rain forests of North-East India.
Pitcher plants (Nepenthes) are found in the humid tropical rain forests of North-East India.
Q14. Why do we need to be repeatedly vaccinated for influenza viruses?
Correct Answer: (b)
Influenza viruses frequently undergo antigenic variation by altering their surface proteins, allowing them to evade immune memory and necessitating repeated vaccination.
Influenza viruses frequently undergo antigenic variation by altering their surface proteins, allowing them to evade immune memory and necessitating repeated vaccination.
Q15. Which of the following statements about nitrogen fixation is correct?
(i) Nitrogenase is only catalytic under anaerobic conditions.
(ii) The energy for nitrogen fixation can be provided by either photosynthesis or respiration only.
(iii) In nitrogen fixation, nitrogen is reduced by the addition of three successive pairs of hydrogen atoms.
(iv) Most nitrogen fixing microbes are aerobic.
(i) Nitrogenase is only catalytic under anaerobic conditions.
(ii) The energy for nitrogen fixation can be provided by either photosynthesis or respiration only.
(iii) In nitrogen fixation, nitrogen is reduced by the addition of three successive pairs of hydrogen atoms.
(iv) Most nitrogen fixing microbes are aerobic.
Correct Answer: (c)
Statement (i) is correct (nitrogenase is oxygen-sensitive) and (iii) is correct ($ → $ requires 6H). Most nitrogen fixers are not necessarily aerobic (many are anaerobic or symbiotic).
Statement (i) is correct (nitrogenase is oxygen-sensitive) and (iii) is correct ($ → $ requires 6H). Most nitrogen fixers are not necessarily aerobic (many are anaerobic or symbiotic).
Q16. What is the relationship between mutations and evolution?
Correct Answer: (b)
Mutations are the ultimate source of genetic variation. By altering DNA sequences, they create new alleles within a population. While most mutations are neutral or harmful, occasionally some provide an advantage, and these variations serve as the raw material for natural selection and evolution to act upon.
Mutations are the ultimate source of genetic variation. By altering DNA sequences, they create new alleles within a population. While most mutations are neutral or harmful, occasionally some provide an advantage, and these variations serve as the raw material for natural selection and evolution to act upon.
Q17. Consider the following statements regarding gymnosperms and choose the correct option.
(i) In gymnosperms, the male and female gametophytes have an independent existence.
(ii) The multicellular female gametophyte is retained within the megasporangium.
(iii) The gymnosperms are heterosporous.
Of these statements
(i) In gymnosperms, the male and female gametophytes have an independent existence.
(ii) The multicellular female gametophyte is retained within the megasporangium.
(iii) The gymnosperms are heterosporous.
Of these statements
Correct Answer: (d)
In gymnosperms, gametophytes are not free-living; they remain within the sporangia on the sporophyte.
In gymnosperms, gametophytes are not free-living; they remain within the sporangia on the sporophyte.
Q18. Which of the following type of ecosystem is expected in an area where evaporation exceeds precipitation, and mean annual rainfall is bellow 100mm
Correct Answer: (c)
Deserts are characterized by extremely low precipitation and high evaporation rates.
Deserts are characterized by extremely low precipitation and high evaporation rates.
Q19. Select the correct statement with respect to mitosis.
Correct Answer: (d)
Alignment at the equatorial plate is the hallmark of metaphase. Chromatids separate in anaphase, and organelles disappear by the end of prophase.
Alignment at the equatorial plate is the hallmark of metaphase. Chromatids separate in anaphase, and organelles disappear by the end of prophase.
Q20. Which of the following is used as an experimental material for making rapid advances in tracing path of carbon in Calvin cycle & other photosynthetic research ?
Correct Answer: (a)
Calvin used unicellular green algae like Chlorella and Scenedesmus in his radioactive carbon labeling experiments.
Calvin used unicellular green algae like Chlorella and Scenedesmus in his radioactive carbon labeling experiments.
Q21. If you wanted to cure allergies by bioengineering an antibody that would bind and disable the antibody responsible for allergic reactions, which would you target?
Correct Answer: (c)
IgE antibodies are responsible for allergic reactions by binding to mast cells and triggering histamine release. Neutralizing IgE would therefore reduce or prevent allergic responses.
IgE antibodies are responsible for allergic reactions by binding to mast cells and triggering histamine release. Neutralizing IgE would therefore reduce or prevent allergic responses.
Q22. Match the following columns.
| Column I | Column II |
|---|---|
| A. Aleurone layer | I. Nutrition |
| B. Parthenocarpic fruit | II. Without fertilisation |
| C. Ovule | III. Seed |
| D. Endosperm | IV. Double fertilisation |
Correct Answer: (a)
Aleurone layer provides nutrition; Parthenocarpic fruit develops without fertilisation; Ovule becomes seed; Endosperm is a result of double fertilisation.
Aleurone layer provides nutrition; Parthenocarpic fruit develops without fertilisation; Ovule becomes seed; Endosperm is a result of double fertilisation.
Q23. Which of the following is used to cut DNA at specific base pair sequences?
Correct Answer: (d)
Restriction enzymes (also known as restriction endonucleases) cut DNA at specific base pair sequences. DNA ligase connects pieces of DNA, so choice (A) is incorrect. Choice (B) is incorrect because gel electrophoresis is used to separate DNA fragments according to their size. Polymerase chain reaction (PCR) is used to amplify specific sequences of DNA, so choice (C) is incorrect.
Restriction enzymes (also known as restriction endonucleases) cut DNA at specific base pair sequences. DNA ligase connects pieces of DNA, so choice (A) is incorrect. Choice (B) is incorrect because gel electrophoresis is used to separate DNA fragments according to their size. Polymerase chain reaction (PCR) is used to amplify specific sequences of DNA, so choice (C) is incorrect.
Q24. A fight-or-flight response in the body is controlled by the
Correct Answer: (a)
The sympathetic division is the part of the autonomic nervous system that prepares the body for stressful or emergency situations by increasing heart rate and blood flow to muscles while inhibiting non-essential functions like digestion.
The sympathetic division is the part of the autonomic nervous system that prepares the body for stressful or emergency situations by increasing heart rate and blood flow to muscles while inhibiting non-essential functions like digestion.
Q25. Column-I contains organisms and column-II contains their excretory structures. Choose the correct match from the options given below.
| Column- I (Organism) | Column -II (Excretory structures) |
|---|---|
| A. Cockroach | I. Nephridia |
| B. Cat fish | II. Malpighian tubules |
| C. Earthworm | III. Kidneys |
| D. Balanoglossus | IV. Flame cells |
| E. Flatworm | V. Proboscis gland |
Correct Answer: (d)
A-II; B-III; C-I; D-V; E-IV.
A-II; B-III; C-I; D-V; E-IV.
Q26. Chromosomes having equal or almost equal arms are called
Correct Answer: (a)
The metacentric chromosome has a middle centromere forming two equal arms of the chromosome.
The metacentric chromosome has a middle centromere forming two equal arms of the chromosome.
Q27. Which hormone is responsible for strong uterine contractions during childbirth?
Correct Answer: (b)
Oxytocin acts on the uterine muscle and causes stronger uterine contractions.
Oxytocin acts on the uterine muscle and causes stronger uterine contractions.
Q28. Steroid hormones
Correct Answer: (d)
Steroid hormones are lipophilic (lipid-soluble). This property allows them to diffuse directly across the plasma membrane of target cells. Once inside, they typically bind to intracellular receptors that move into the nucleus to act as transcription factors, directly influencing gene expression.
Steroid hormones are lipophilic (lipid-soluble). This property allows them to diffuse directly across the plasma membrane of target cells. Once inside, they typically bind to intracellular receptors that move into the nucleus to act as transcription factors, directly influencing gene expression.
Q29. Match the medical procedures with their use:
| Procedure | Primary Use |
|---|---|
| A. Amniocentesis | (I) Voluntary abortion |
| B. MTP | (II) Genetic disorder test |
| C. AI | (III) Low sperm count treatment |
Correct Answer: (a)
Clinical procedures described in the text.
Clinical procedures described in the text.
Q30. Amazon rain forest, called the ‘Lungs of the Planet’, contribute following percentage of oxygen by photosynthesis, to earth atmosphere
Correct Answer: (a)
The Amazon rainforest is estimated to produce about 20 percent of the total oxygen in the Earth's atmosphere.
The Amazon rainforest is estimated to produce about 20 percent of the total oxygen in the Earth's atmosphere.
Q31. Refer to the figure, which shows the population of wild rabbits on an island as time progresses.
Which of the following points best approximates the carrying capacity of the island for rabbits?
Which of the following points best approximates the carrying capacity of the island for rabbits?
Correct Answer: (d)
(D) Point D represents the carrying capacity because the population size is stabilizing at point D. Point A represents the lag phase, point B represents exponential growth, and point C represents a population that is starting to decline, so choices (A), (B), and (C) are incorrect.
(D) Point D represents the carrying capacity because the population size is stabilizing at point D. Point A represents the lag phase, point B represents exponential growth, and point C represents a population that is starting to decline, so choices (A), (B), and (C) are incorrect.
Q32. Match the terms/feature given in column I with their examples given in column II and select the correct match from the option given below.
| Column-I (Term/Feature) | Column-II (Examples) |
|---|---|
| A. Gregarious pest | (I) Hirudinaria |
| B. Vector | (II) Planaria |
| C. Oviparous with indirect development | (III) Sepia |
| D. Metameres | (IV) Aedes |
| E. High regeneration capacity | (V) Locust |
Correct Answer: (d)
A-V; B-IV; C-III; D-I; E-II.
A-V; B-IV; C-III; D-I; E-II.
Q33. At which stage, the homologous chromosomes separate due to repulsion, but are yet held by chiasmata ?
Correct Answer: (c)
In diplotene, the homologous chromosomes repel each other and separate except at the chiasmata.
In diplotene, the homologous chromosomes repel each other and separate except at the chiasmata.
Q34. T.S. of monocot leaf is given below, certain parts have been marked by alphabets (A – G). Which one is the option showing there correct labelling?
Correct Answer: (a)
A is upper (adaxial) epidermis; xylem is towards the upper surface; mesophyll is undifferentiated; abaxial epidermis is lower with stomata.
A is upper (adaxial) epidermis; xylem is towards the upper surface; mesophyll is undifferentiated; abaxial epidermis is lower with stomata.
Q35. The charged molecule which is electrically neutral is known as
Correct Answer: (b)
A zwitterion is an ion that has separate positive and negative charges but a net charge of zero.
A zwitterion is an ion that has separate positive and negative charges but a net charge of zero.
Q36. A molecule of CO₂ that is generated in the cardiac muscle of the left ventricle would not pass through which of the following structures before leaving the body?
Correct Answer: (b)
CO₂ produced in the left ventricle enters the coronary circulation, returns to the right atrium, then passes through the right ventricle and lungs before being exhaled. It does not re-enter the left atrium before leaving the body.
CO₂ produced in the left ventricle enters the coronary circulation, returns to the right atrium, then passes through the right ventricle and lungs before being exhaled. It does not re-enter the left atrium before leaving the body.
Q37. In terms of studying gene function, what is the main benefit that genome editing has over RNAi?
Correct Answer: (a)
RNA interference (RNAi) is a 'knockdown' technology that degrades mRNA or blocks translation, resulting in reduced protein levels but often leaving some function intact. Genome editing (like CRISPR/Cas9) creates permanent changes in the DNA sequence, allowing for a complete 'knockout' or total elimination of the gene's function.
RNA interference (RNAi) is a 'knockdown' technology that degrades mRNA or blocks translation, resulting in reduced protein levels but often leaving some function intact. Genome editing (like CRISPR/Cas9) creates permanent changes in the DNA sequence, allowing for a complete 'knockout' or total elimination of the gene's function.
Q38. Organelle important in spindle formation during nuclear division is
Correct Answer: (c)
Centrioles form the basal body of cilia and flagella and spindle fibers that give rise to the spindle apparatus during cell division in animal cells.
Centrioles form the basal body of cilia and flagella and spindle fibers that give rise to the spindle apparatus during cell division in animal cells.
Q39. Match the following statistics (2011):
| Metric | Value |
|---|---|
| A. India's population | (I) Less than 2% |
| B. World population | (II) 1.2 billion |
| C. Growth rate | (III) 7.2 billion |
Correct Answer: (a)
Census 2011 data from section 3.2.
Census 2011 data from section 3.2.
Q40. Keel is the characteristic feature of flower of
Correct Answer: (a)
Indigofera belongs to Fabaceae, which has papilionaceous corolla with a 'keel' (two fused anterior petals).
Indigofera belongs to Fabaceae, which has papilionaceous corolla with a 'keel' (two fused anterior petals).
Q41. The difference between the amphibian and mammal hearts is that
Correct Answer: (c)
Amphibians have a three-chambered heart with a single ventricle, but internal ridges and channels partially separate oxygenated and deoxygenated blood, reducing mixing. Mammals, in contrast, have complete separation with a four-chambered heart.
Amphibians have a three-chambered heart with a single ventricle, but internal ridges and channels partially separate oxygenated and deoxygenated blood, reducing mixing. Mammals, in contrast, have complete separation with a four-chambered heart.
Q42. Which of the following statements is not true?
Correct Answer: (a)
Not all arteries carry oxygenated blood (e.g., pulmonary arteries carry deoxygenated blood), and not all veins carry deoxygenated blood (pulmonary veins carry oxygenated blood). The other statements correctly describe vascular structure and regulation.
Not all arteries carry oxygenated blood (e.g., pulmonary arteries carry deoxygenated blood), and not all veins carry deoxygenated blood (pulmonary veins carry oxygenated blood). The other statements correctly describe vascular structure and regulation.
Q43. Blood clots are made of
Correct Answer: (a)
Blood clots consist primarily of fibrin, an insoluble protein formed from fibrinogen during the clotting cascade. Prothrombin is a clotting factor but is not a structural component of the clot itself.
Blood clots consist primarily of fibrin, an insoluble protein formed from fibrinogen during the clotting cascade. Prothrombin is a clotting factor but is not a structural component of the clot itself.
Q44. Which of the following is a sexually transmitted infection (STI) that is not completely curable?
Correct Answer: (c)
Except for hepatitis-B, genital herpes and HIV infections, other diseases are completely curable.
Except for hepatitis-B, genital herpes and HIV infections, other diseases are completely curable.
Q45. Which are correct for 'Cyanobacteria'?
(i) They are autotrophic microbes.
(ii) They add organic matter to the soil.
(iii) They are used as biofertilisers in paddy fields.
(i) They are autotrophic microbes.
(ii) They add organic matter to the soil.
(iii) They are used as biofertilisers in paddy fields.
Correct Answer: (a)
Standard biofertiliser facts (section 8.6).
Standard biofertiliser facts (section 8.6).
Q46. You have identified a calcium storage disease in rats. How would this inability to store Ca2+ affect muscle contraction?
Correct Answer: (b)
During muscle contraction, calcium ions bind to troponin. This binding causes tropomyosin to shift away from actin’s myosin-binding sites, allowing cross-bridge formation. If Ca2+ cannot bind to troponin, the binding sites remain blocked, preventing muscle contraction.
During muscle contraction, calcium ions bind to troponin. This binding causes tropomyosin to shift away from actin’s myosin-binding sites, allowing cross-bridge formation. If Ca2+ cannot bind to troponin, the binding sites remain blocked, preventing muscle contraction.
Q47. Which of the following are characteristics of an 'Ideal Contraceptive'?
(i) User-friendly and easily available.
(ii) Effective and reversible.
(iii) Should interfere with sexual drive.
(i) User-friendly and easily available.
(ii) Effective and reversible.
(iii) Should interfere with sexual drive.
Correct Answer: (a)
An ideal contraceptive should not in any way interfere with sexual drive.
An ideal contraceptive should not in any way interfere with sexual drive.
Q48. T. O. Diener discovered a new infectious agent that was smaller than viruses and have the following characteristics.
(i) It causes potato spindle tuber disease.
(ii) It has free RNA.
(iii) Molecular weight of RNA is low.
Identify the infections agent.
(i) It causes potato spindle tuber disease.
(ii) It has free RNA.
(iii) Molecular weight of RNA is low.
Identify the infections agent.
Correct Answer: (b)
Viroids, discovered by Diener in 1971, are infectious agents smaller than viruses consisting only of low-molecular-weight free RNA without a protein coat.
Viroids, discovered by Diener in 1971, are infectious agents smaller than viruses consisting only of low-molecular-weight free RNA without a protein coat.
Q49. The cross section of a trunk of tree shows 50 annual rings, the age of tree is
Correct Answer: (b)
Since each annual ring represents one year's growth, 50 rings correspond to 50 years.
Since each annual ring represents one year's growth, 50 rings correspond to 50 years.
Q50. What is true about the phosphorus cycle?
A. Rocks are the natural reservoirs of phosphorus.
B. Weathering of sedimentary rocks makes phosphate available to the soil.
C. Nitrosomonas play a key role in fixing phosphorus to the soil.
D. Herbivores and carnivores obtain phosphorus from plant directly or indirectly.
A. Rocks are the natural reservoirs of phosphorus.
B. Weathering of sedimentary rocks makes phosphate available to the soil.
C. Nitrosomonas play a key role in fixing phosphorus to the soil.
D. Herbivores and carnivores obtain phosphorus from plant directly or indirectly.
Correct Answer: (d)
A, B, and D are correct. Statement C is incorrect because Nitrosomonas is a nitrogen-fixing bacterium involved in the nitrogen cycle.
A, B, and D are correct. Statement C is incorrect because Nitrosomonas is a nitrogen-fixing bacterium involved in the nitrogen cycle.
Q51. How can we separate leaf pigments of any green plant?
Correct Answer: (b)
Paper chromatography is a standard technique used to separate and identify the different pigments present in a leaf (chlorophyll a, chlorophyll b, xanthophylls, and carotenoids).
Paper chromatography is a standard technique used to separate and identify the different pigments present in a leaf (chlorophyll a, chlorophyll b, xanthophylls, and carotenoids).
Q52. How much portion of the photosynthetically active radiation (PAR) is captured by the plants?
Correct Answer: (d)
Of the incident solar radiation, less than 50% is PAR. Plants capture only 2-10% of this PAR for photosynthesis.
Of the incident solar radiation, less than 50% is PAR. Plants capture only 2-10% of this PAR for photosynthesis.
Q53. Naked cytoplasm, multinucleated and saprophytic are the characteristics of
Correct Answer: (d)
Slime molds are saprophytic protists that form a multinucleated mass of protoplasm called plasmodium.
Slime molds are saprophytic protists that form a multinucleated mass of protoplasm called plasmodium.
Q54. The reactions of Calvin cycle not directly dependent on light, but they usually do not occur at night. Why?
Correct Answer: (d)
The Calvin cycle requires a continuous supply of ATP and NADPH, which are only generated during the light-dependent phase.
The Calvin cycle requires a continuous supply of ATP and NADPH, which are only generated during the light-dependent phase.
Q55. An important function of the excretory system is to eliminate excess nitrogen produced by metabolic processes. Which of the following organisms is most efficient at packaging nitrogen for excretion?
Correct Answer: (c)
Iguanas excrete nitrogen primarily as uric acid, which is relatively non-toxic and requires very little water for elimination. This makes uric acid the most efficient form of nitrogen packaging among the options given.
Iguanas excrete nitrogen primarily as uric acid, which is relatively non-toxic and requires very little water for elimination. This makes uric acid the most efficient form of nitrogen packaging among the options given.
Q56. Prokaryotic genomes are packaged into ________ chromosomes in the ________.
Correct Answer: (a)
(A) Prokaryotes have circular chromosomes in the nucleoid region of their cells. Choice (B) is incorrect because prokaryotes do not have a nucleus. Choices (C) and (D) are incorrect because prokaryotes do not have linear chromosomes; eukaryotes have linear chromosomes.
(A) Prokaryotes have circular chromosomes in the nucleoid region of their cells. Choice (B) is incorrect because prokaryotes do not have a nucleus. Choices (C) and (D) are incorrect because prokaryotes do not have linear chromosomes; eukaryotes have linear chromosomes.
Q57. Swimming underwater using forelimbs for propulsion is similar to flying through the air because
Correct Answer: (d)
Both swimming and flying rely on generating lift by pushing against a fluid medium (water or air). By exerting a downward force on the surrounding fluid, an upward lift force is generated, allowing the organism to remain suspended or move efficiently against gravity.
Both swimming and flying rely on generating lift by pushing against a fluid medium (water or air). By exerting a downward force on the surrounding fluid, an upward lift force is generated, allowing the organism to remain suspended or move efficiently against gravity.
Q58. Match the embryonic layers with their types:
| Column-I (Layer) | Column-II (Type) |
|---|---|
| A. Ectoderm | (I) Inner layer |
| B. Mesoderm | (II) Outer layer |
| C. Endoderm | (III) Middle layer |
Correct Answer: (a)
Standard embryonic layer positions.
Standard embryonic layer positions.
Q59. Identify the correct characteristics of porifera.
(i) Commonly known as sea walnuts.
(ii) Presence of ostia and collar cells.
(iii) Exhibit tissue level of characteristics.
(iv) It is the largest phylum of animal kingdom.
(v) The body is supported by spicules and sponging fibers.
(vi) Contains cnidocytes which is used for defense, anchorage and capturing of prey.
(i) Commonly known as sea walnuts.
(ii) Presence of ostia and collar cells.
(iii) Exhibit tissue level of characteristics.
(iv) It is the largest phylum of animal kingdom.
(v) The body is supported by spicules and sponging fibers.
(vi) Contains cnidocytes which is used for defense, anchorage and capturing of prey.
Correct Answer: (a)
Characteristics of Porifera include (ii) ostia/collar cells and (v) spicules/spongin fibers. (i) refers to Ctenophora, (iii) is tissue level (Cnidaria), (iv) is Arthropoda, (vi) is Cnidaria.
Characteristics of Porifera include (ii) ostia/collar cells and (v) spicules/spongin fibers. (i) refers to Ctenophora, (iii) is tissue level (Cnidaria), (iv) is Arthropoda, (vi) is Cnidaria.
Q60. Japanese four o’clocks that are red and tall are crossed to white short ones, producing an F1 that is pink and tall. If these genes assort independently, and the F1 is self-crossed, what would you predict for the ratio of F2 phenotypes?
Correct Answer: (d)
Color shows incomplete dominance (1 red : 2 pink : 1 white) and height shows simple dominance (3 tall : 1 short). Using the product rule: (1 Red + 2 Pink + 1 White) × (3 Tall + 1 Short) = 3 Red Tall, 1 Red Short, 6 Pink Tall, 2 Pink Short, 3 White Tall, 1 White Short. Sorting these leads to choice D.
Color shows incomplete dominance (1 red : 2 pink : 1 white) and height shows simple dominance (3 tall : 1 short). Using the product rule: (1 Red + 2 Pink + 1 White) × (3 Tall + 1 Short) = 3 Red Tall, 1 Red Short, 6 Pink Tall, 2 Pink Short, 3 White Tall, 1 White Short. Sorting these leads to choice D.
Q61. One of the primary function of the ground tissue in a plant is
Correct Answer: (a)
Ground tissue includes the mesophyll of leaves, where the majority of photosynthesis takes place.
Ground tissue includes the mesophyll of leaves, where the majority of photosynthesis takes place.
Q62. Which one of the following is not an inclusion body found in prokaryotes?
Correct Answer: (c)
Inclusion bodies are for storage (granules). A polysome is a complex of ribosomes and mRNA involved in translation.
Inclusion bodies are for storage (granules). A polysome is a complex of ribosomes and mRNA involved in translation.
Q63. Stabilizing selection differs from directional selection because
Correct Answer: (a)
Stabilizing selection acts against extreme phenotypes and favors the intermediate, 'average' individuals, which reduces the overall variance of the population without shifting the mean. Directional selection favors one extreme over the other, causing the population mean to shift in that direction over generations.
Stabilizing selection acts against extreme phenotypes and favors the intermediate, 'average' individuals, which reduces the overall variance of the population without shifting the mean. Directional selection favors one extreme over the other, causing the population mean to shift in that direction over generations.
Q64. During exercise more oxygen is delivered to the muscles because
Correct Answer: (c)
Exercise triggers the Bohr effect: increased CO2 production lowers blood pH, which decreases hemoglobin's affinity for oxygen, causing it to 'unload' O2 more readily. Additionally, increased muscle temperature further reduces hemoglobin affinity, facilitating even more oxygen delivery to the working tissues.
Exercise triggers the Bohr effect: increased CO2 production lowers blood pH, which decreases hemoglobin's affinity for oxygen, causing it to 'unload' O2 more readily. Additionally, increased muscle temperature further reduces hemoglobin affinity, facilitating even more oxygen delivery to the working tissues.
Q65. Which of the following statements is accurate for DNA replication in your cells, but not PCR?
Correct Answer: (c)
During in vivo DNA replication, the lagging strand is synthesized in short Okazaki fragments that must be joined together by the enzyme DNA ligase. In PCR, the target sequence is typically small enough that the polymerase completes the entire strand from a single primer, and there are no fragments to seal. Furthermore, PCR uses heat-stable Taq polymerase, whereas human cells use heat-labile polymerases.
During in vivo DNA replication, the lagging strand is synthesized in short Okazaki fragments that must be joined together by the enzyme DNA ligase. In PCR, the target sequence is typically small enough that the polymerase completes the entire strand from a single primer, and there are no fragments to seal. Furthermore, PCR uses heat-stable Taq polymerase, whereas human cells use heat-labile polymerases.
Q66. Match the secondary metabolite with its category (Table 9.3):
| Column I (Metabolite) | Column II (Category) |
|---|---|
| A. Morphine | (I) Toxin |
| B. Monoterpenes | (II) Alkaloid |
| C. Abrin | (III) Terpenoides |
| D. Curcumin | (IV) Drug |
Correct Answer: (a)
Data from the summary table in Unit VIII.
Data from the summary table in Unit VIII.
Q67. Two snowshoe hares (a type of rabbit) have the same genotype. During the winter, the hare that lives outdoors in the cold has white fur, but the hare that lives in a climate-controlled and warm environment has brown fur. This is an example of ________.
Correct Answer: (d)
(D) Phenotypic plasticity describes the ability of two individuals with the same genotype to produce different phenotypes, depending on the different environmental factors that affect each individual. Choice (A) is incorrect because sex-linkage involves traits found on the sex chromosomes. Multiple gene inheritance refers to multiple genes contributing to an individual’s phenotype, so choice (B) is incorrect. Nonnuclear inheritance refers to traits coded for by genes outside of the nucleus (in the mitochondria or chloroplast), so choice (C) is incorrect.
(D) Phenotypic plasticity describes the ability of two individuals with the same genotype to produce different phenotypes, depending on the different environmental factors that affect each individual. Choice (A) is incorrect because sex-linkage involves traits found on the sex chromosomes. Multiple gene inheritance refers to multiple genes contributing to an individual’s phenotype, so choice (B) is incorrect. Nonnuclear inheritance refers to traits coded for by genes outside of the nucleus (in the mitochondria or chloroplast), so choice (C) is incorrect.
Q68. In the composition of cellular mass, arrange the components- proteins(P), carbohydrates(C), lipids(L) and nucleic acids(N) in decreasing order of mass percentage.
Correct Answer: (b)
Average cellular composition: Proteins (10-15%) > Nucleic Acids (5-7%) > Carbohydrates (3%) > Lipids (2%).
Average cellular composition: Proteins (10-15%) > Nucleic Acids (5-7%) > Carbohydrates (3%) > Lipids (2%).
Q69. A plant lacking the WOODEN LEG gene will likely
Correct Answer: (c)
The WOODEN LEG mutation results in a failure of phloem differentiation. Without functional phloem, the plant is incapable of transporting the products of photosynthesis (photosynthate) to its roots and other sinks.
The WOODEN LEG mutation results in a failure of phloem differentiation. Without functional phloem, the plant is incapable of transporting the products of photosynthesis (photosynthate) to its roots and other sinks.
Q70. When we homogenise any tissue in an acid the acid soluble pool represents
Correct Answer: (a)
The acid-soluble pool roughly represents the cytoplasmic composition, containing small molecules, while organelles and membranes are in the insoluble fraction.
The acid-soluble pool roughly represents the cytoplasmic composition, containing small molecules, while organelles and membranes are in the insoluble fraction.
Q71. The following is a list of the components of a chemical synapse. A mutation in the structure of which of these would affect only the reception of the message, not its release or the response?
Correct Answer: (a)
Membrane proteins on the postsynaptic cell include the receptors that specifically bind to neurotransmitters. A mutation here would specifically block the 'reception' of the chemical signal from the cleft, without preventing the presynaptic cell from releasing the neurotransmitter or the postsynaptic cell from responding internally once a signal is received.
Membrane proteins on the postsynaptic cell include the receptors that specifically bind to neurotransmitters. A mutation here would specifically block the 'reception' of the chemical signal from the cleft, without preventing the presynaptic cell from releasing the neurotransmitter or the postsynaptic cell from responding internally once a signal is received.
Q72. Which of the following is true for MTP in India?
(i) Legalised in 1971.
(ii) Used to get rid of unwanted pregnancy due to rape.
(iii) Essential if the pregnancy is harmful to the mother.
(i) Legalised in 1971.
(ii) Used to get rid of unwanted pregnancy due to rape.
(iii) Essential if the pregnancy is harmful to the mother.
Correct Answer: (a)
Legality and conditions for MTP (Page 46).
Legality and conditions for MTP (Page 46).
Q73. Assertion: Oogenesis is initiated during the embryonic development stage.
Reason: No more oogonia are formed and added after birth.
Correct Answer: (a)
The total number of potential eggs is determined before birth.
The total number of potential eggs is determined before birth.
Q74. As you sit quietly reading this sentence, the part of the nervous system that is most active is the
Correct Answer: (c)
The parasympathetic nervous system is the 'rest and digest' division of the autonomic nervous system. It predominates during periods of relaxation and low stress, maintaining homeostatic functions and conserving energy.
The parasympathetic nervous system is the 'rest and digest' division of the autonomic nervous system. It predominates during periods of relaxation and low stress, maintaining homeostatic functions and conserving energy.
Q75. During an action potential
Correct Answer: (d)
Depolarization (the rising phase) is driven by the opening of voltage-gated Na+ channels, allowing sodium to enter the cell. Repolarization (the falling phase) occurs when these channels close and voltage-gated K+ channels open, allowing potassium to leave the cell (efflux).
Depolarization (the rising phase) is driven by the opening of voltage-gated Na+ channels, allowing sodium to enter the cell. Repolarization (the falling phase) occurs when these channels close and voltage-gated K+ channels open, allowing potassium to leave the cell (efflux).
Q76. Regarding general characteristics of plants, which statement is correct.
A. Some of these may be partially heterotrophic as in case of insectivorous plants like Venus fly trap.
B. They have distinct nucleus, chloroplast and chitinous cell wall.
A. Some of these may be partially heterotrophic as in case of insectivorous plants like Venus fly trap.
B. They have distinct nucleus, chloroplast and chitinous cell wall.
Correct Answer: (a)
Plant cell walls are primarily cellulosic, not chitinous (which is characteristic of fungi).
Plant cell walls are primarily cellulosic, not chitinous (which is characteristic of fungi).
Q77. A student was given a sample to observe under the microscope. He observed and found that the sample is the most common type of spore involved in asexual reproduction in algae. Identify the spore.
Correct Answer: (a)
Zoospores are the most common asexual spores in algae; they are typically flagellated and motile.
Zoospores are the most common asexual spores in algae; they are typically flagellated and motile.
Q78. During mitosis, nuclear envelope, nucleolous begin to form and ER to reappear at ______
Correct Answer: (d)
Telophase is the final stage where the nuclear envelope reforms around chromosome clusters, and the nucleolus, Golgi, and ER reappear.
Telophase is the final stage where the nuclear envelope reforms around chromosome clusters, and the nucleolus, Golgi, and ER reappear.
Q79. Leopard frogs from different geographic populations of the Rana pipiens complex
Correct Answer: (b)
Although they appear morphologically similar, the various populations within the Rana pipiens complex exhibit different mating calls (prezygotic isolation) and their hybrids often fail to develop properly (postzygotic isolation), classifying them as distinct biological species.
Although they appear morphologically similar, the various populations within the Rana pipiens complex exhibit different mating calls (prezygotic isolation) and their hybrids often fail to develop properly (postzygotic isolation), classifying them as distinct biological species.
Q80. After the first mitotic division of the zygote, the larger of the two cells becomes the
Correct Answer: (c)
The zygote divides asymmetrically to form a smaller apical cell and a larger basal cell. The apical cell gives rise to the embryo, while the larger basal cell divides to form the suspensor.
The zygote divides asymmetrically to form a smaller apical cell and a larger basal cell. The apical cell gives rise to the embryo, while the larger basal cell divides to form the suspensor.
Q81. At physiological pH, for the formation of ammonium ion, ammonia is:
Correct Answer: (a)
At physiological pH, ammonia (NH3) picks up a proton (H+) to form the ammonium ion (NH4+).
At physiological pH, ammonia (NH3) picks up a proton (H+) to form the ammonium ion (NH4+).
Q82. Huntington’s disease is caused by a short tandem CAG repeat in the HTT gene. Individuals with fewer than 35 CAG repeats in the HTT gene do not develop Huntington’s disease. Individuals with 40 or more CAG repeats will develop Huntington’s disease.
A transgenic mouse has the HTT gene. A scientist wants to investigate whether inserting a stop codon into the HTT gene might prevent the mouse from developing the disease. Which of the following tools would be most useful in inserting a stop codon into the HTT gene?
A transgenic mouse has the HTT gene. A scientist wants to investigate whether inserting a stop codon into the HTT gene might prevent the mouse from developing the disease. Which of the following tools would be most useful in inserting a stop codon into the HTT gene?
Correct Answer: (a)
CRISPR-Cas9 is used for gene editing, and with the correct donor DNA, it could be used to insert a stop codon into a gene. Gel electrophoresis separates DNA fragments by size, so choice (B) is incorrect. Choice (C) is incorrect because PCR amplifies the number of copies of a specific DNA sequence. Restriction enzymes cut DNA at specific sequences, so choice (D) is incorrect.
CRISPR-Cas9 is used for gene editing, and with the correct donor DNA, it could be used to insert a stop codon into a gene. Gel electrophoresis separates DNA fragments by size, so choice (B) is incorrect. Choice (C) is incorrect because PCR amplifies the number of copies of a specific DNA sequence. Restriction enzymes cut DNA at specific sequences, so choice (D) is incorrect.
Q83. The map given below indicates the former and the present distribution of an animal. Which animal could it be?
Correct Answer: (d)
The map shows the distribution of the Asiatic Lion, which was once found across much of Northern India but is now restricted to the Gir Forest in Gujarat.
The map shows the distribution of the Asiatic Lion, which was once found across much of Northern India but is now restricted to the Gir Forest in Gujarat.
Q84. What potential problems must be considered in creating a transgenic bacterium with the human insulin gene isolated from genomic DNA to produce insulin?
Correct Answer: (b)
Human insulin is synthesized as a precursor (proinsulin) that requires eukaryotic-specific post-translational modifications, including the formation of disulfide bonds and the enzymatic cleavage of the C-peptide in the Golgi apparatus. Bacteria lack these organelles and specialized processing enzymes, so they cannot produce active insulin from a simple genomic gene sequence without additional engineering.
Human insulin is synthesized as a precursor (proinsulin) that requires eukaryotic-specific post-translational modifications, including the formation of disulfide bonds and the enzymatic cleavage of the C-peptide in the Golgi apparatus. Bacteria lack these organelles and specialized processing enzymes, so they cannot produce active insulin from a simple genomic gene sequence without additional engineering.
Q85. Refer the given figures A, B, C and D and identify the option which shows their correct name.
Correct Answer: (a)
A: Pleurobrachia, B: Cnidoblast, C: Aurelia, D: Adamsia.
A: Pleurobrachia, B: Cnidoblast, C: Aurelia, D: Adamsia.
Q86. In comparing gene expression in prokaryotes and eukaryotes
Correct Answer: (d)
Eukaryotes can produce multiple proteins from a single gene through alternative splicing. Additionally, in both domains, the mRNA is colinear with the protein, meaning the linear sequence of nucleotides in the mRNA (post-splicing in eukaryotes) corresponds directly to the linear sequence of amino acids in the protein.
Eukaryotes can produce multiple proteins from a single gene through alternative splicing. Additionally, in both domains, the mRNA is colinear with the protein, meaning the linear sequence of nucleotides in the mRNA (post-splicing in eukaryotes) corresponds directly to the linear sequence of amino acids in the protein.
Q87. Which of the following statements is incorrect ?
Correct Answer: (d)
Porifera includes fresh water species like Spongilla.
Porifera includes fresh water species like Spongilla.
Q88. An osmoregulator would maintain its internal fluids at a concentration that is ____ relative to its surroundings.
Correct Answer: (d)
Osmoregulators actively control their internal osmotic concentration and may maintain body fluids that are hypertonic, hypotonic, or isotonic relative to the external environment, depending on ecological conditions.
Osmoregulators actively control their internal osmotic concentration and may maintain body fluids that are hypertonic, hypotonic, or isotonic relative to the external environment, depending on ecological conditions.
Q89. If you have type AB blood, which of the following results would be expected?
Correct Answer: (c)
Individuals with AB blood type express both A and B antigens on their red blood cells. Therefore, their blood will agglutinate when exposed to either anti-A or anti-B antibodies.
Individuals with AB blood type express both A and B antigens on their red blood cells. Therefore, their blood will agglutinate when exposed to either anti-A or anti-B antibodies.
Q90. Biological control of pests relies on ______ rather than chemicals.
Correct Answer: (b)
Page 8 states that biological control relies on natural predation.
Page 8 states that biological control relies on natural predation.