Q23. The principle of competetive exclusion was stated by
Correct Answer: (b)
Gause's principle states two species can't occupy the same niche indefinitely.
Q24. Interspecific hybridization is the mating of
Correct Answer: (b)
Hybridization between different species (e.g., mule).
Q25. Graves' disease is caused due to
Correct Answer: (b)
Hyperthyroidism leads to Graves' disease.
Q26. Which of the following is the correct sequence of events in 'the origin of life' ? I. Formation of protobionts II. Synthesis of organic monomers III. Synthesis of organic polymers IV. Formation of DNA-based genetic systems
Correct Answer: (c)
Standard chemical evolution sequence.
Q27. Methanogens belong to
Correct Answer: (b)
Methanogens are specialized Archaebacteria found in anaerobic habitats.
Q28. Which of the following is hormone-releasing IUD?
Q29. How many hot spots of biodiversity in the world have been identified till date by Norman Myers?
Correct Answer: (c)
Currently, there are 34 identified biodiversity hotspots globally.
Q30. Which of the following sets of diseases is caused by bacteria?
Correct Answer: (a)
Vibrio cholerae and Clostridium tetani are bacteria.
Q31. Match Column-I with Column-II and select the correct option using the codes given below :
a. Citric acid
(i) Trichoderma
b. Cyclosporin A
(ii) Clostridium
c. Statins
(iii) Aspergillus
d. Butyric acid
(iv) Monascus
Correct Answer: (b)
a-iii, b-i, c-iv, d-ii.
Q32. Cortex is the region found between
Correct Answer: (a)
Cortex represents the ground tissue between the epidermis and the stele.
Q33. A true breeding plant is
Correct Answer: (c)
True breeding implies homozygosity and stable inheritance of traits.
Q34. Choose the correct statement.
Correct Answer: (c)
Rods and cones hyperpolarize when exposed to light.
Q35. Serum differs from blood in
Correct Answer: (c)
Serum = Plasma minus Clotting factors.
Q36. Which of the following restriction enzymes produces blunt ends?
Correct Answer: (b)
Eco RV cuts both strands squarely at the same point.
Q37. Study the four statements (A-D) given below and select the two correct ones out of them : A. Definition of biological species was given by Ernst Mayr. B. Photoperiod does not affect reproduction in plants. C. Binomial nomenclature system was given by R. H. Whittaker. D. In unicellular organisms, reproduction is synonymous with growth.
Correct Answer: (c)
A and D are correct; B is wrong (photoperiod is vital); C is wrong (Linnaeus).
Q38. You are given a tissue with its potential for differentiation in an artificial culture. Which of the following pairs of hormones would you add to the medium to secure shoots as well as roots?
Correct Answer: (b)
The balance of Auxin (roots) and Cytokinin (shoots) is essential for morphogenesis.
Q39. Oxidative phosphorylation is
Correct Answer: (d)
It uses energy from substrate oxidation to create an electrochemical gradient for ATP.
Q40. A non-proteinaceous enzyme is
Correct Answer: (b)
Ribozymes are catalytic RNA molecules.
Q41. The balloon-shaped structures called tyloses
Correct Answer: (c)
Tyloses are ingrowths of xylem parenchyma into vessel lumens, often blocking them.
Q42. The posterior pituitary gland is not a 'true' endocrine gland because
Correct Answer: (b)
It stores/releases Oxytocin and ADH, synthesized in the hypothalamus.
Q43. A lake which is rich in organic waste may result in
Correct Answer: (d)
Eutrophication leads to oxygen depletion and fish kill.
Q44. Which kind of therapy was given in 1990 to a four-year-old girl with adenosine deaminase (ADA) deficiency?
Correct Answer: (a)
The first clinical gene therapy trial was for ADA deficiency.
Q45. Which one of the following statements is wrong ?
Correct Answer: (b)
Algin is obtained from brown algae (Phaeophyceae) and carrageenan from red algae (Rhodophyceae).
Q46. Radial symmetry is found in the flowers of
Correct Answer: (a)
Brassica (Mustard) has actinomorphic (radial) symmetry.
Q47. The highest DDT concentration in aquatic food chain shall occur in
Correct Answer: (b)
Biomagnification is highest at the top trophic level (seagull).
Q48. Which is essential for the growth of root tip?
Correct Answer: (c)
Calcium is required for cell division and the formation of the cell plate.
Q49. Which of the following is the least likely to be involved in stabilizing the three-dimensional folding of most proteins?
Correct Answer: (d)
Ester bonds are not typically involved in protein folding.
Q50. DNA-dependent RNA polymerase catalyzes transcription on one strand of the DNA which is called the
Correct Answer: (a)
The mRNA is synthesized on the template strand.
Q51. Name a peptide hormone which acts mainly on hepatocytes, adipocytes and enhances cellular glucose uptake and utilization.
Correct Answer: (a)
Insulin is the primary hypoglycemic hormone.
Q52. Match Column-I with Column-II for housefly classification and select the correct option using the codes given below :
a. Family
(i) Diptera
b. Order
(ii) Arthropoda
c. Class
(iii) Muscidae
d. Phylum
(iv) Insecta
Correct Answer: (a)
Musca domestica: Family Muscidae, Order Diptera, Class Insecta, Phylum Arthropoda.
Q53. Which of the following is Incorrect regarding vasectomy?
Correct Answer: (b)
Sperms are still present in the epididymis; they just can't exit via the duct.
Q54. The term 'polyadelphous' is related to
Correct Answer: (b)
Polyadelphous refers to stamens united into many bundles.
Q55. A foreign DNA and plasmid cut by the same restriction endonuclease can be joined to form a recombinant plasmid using
Correct Answer: (d)
DNA ligase joins the sugar-phosphate backbones.
Q56. Match Column-I with Column-II and select the correct option using the codes given below:
Correct Answer: (b)
Large central vacuoles are characteristic of plant cells; animal cells have small, temporary vacuoles.
Q63. Which of the following biomolecules is common to respiration-mediated breakdown of fats, carbohydrates and proteins?
Correct Answer: (d)
Acetyl CoA is the common intermediate where various metabolic pathways converge into the Krebs cycle.
Q64. During cell growth, DNA synthesis takes place in
Correct Answer: (a)
Replication of DNA occurs during the Synthesis (S) phase of the cell cycle.
Q65. Phytochrome is a
Correct Answer: (d)
Phytochrome is a pigment-bearing protein (chromoprotein).
Q66. Smooth muscles are
Correct Answer: (a)
Smooth muscles are non-striated, involuntary, and spindle-shaped.
Q67. Osteoporosis, an age-related disease of skeletal system, may occur due to
Correct Answer: (c)
Post-menopausal estrogen deficiency leads to bone loss.
Q68. Genetic drift operates in
Correct Answer: (a)
Drift is significant in small, isolated populations.
Q69. Conifers are adapted to tolerate extreme environmental conditions because of
Correct Answer: (c)
Thick cuticles and sunken stomata are key xerophytic adaptations in conifers.
Q70. Which of the following describes the given graph correctly?
Correct Answer: (b)
Exothermic (product lower than substrate); A is catalyzed activation energy.
Q71. A few drops of sap were collected by cutting across a plant stem by a suitable method. The sap was tested chemically. Which one of the following test results indicates that it is phloem sap ?
Correct Answer: (b)
Phloem sap is alkaline (pH 7.5 - 8.5) and contains sucrose.
Q72. How many plants among Indigofera, Sesbania, Salvia, Allium, Aloe, mustard, groundnut, radish, gram and turnip have stamens with different lengths in their flowers?
Correct Answer: (b)
Mustard, Radish, Turnip (tetradynamous) and Salvia have stamens of different lengths.
Q73. The part of nephron involved in active reabsorption of sodium is
Correct Answer: (b)
70-80% of electrolytes are reabsorbed in the PCT.
Q74. Which of the following is correct regarding AIDS causative agent HIV?
Correct Answer: (b)
HIV has 2 identical RNA strands and 2 Reverse Transcriptase enzymes.
Q75. The primary producers of the deep-sea hydrothermal vent ecosystem are
Correct Answer: (b)
Without light, chemosynthetic bacteria use chemical energy to produce organic matter.
Q76. Taylor conducted the experiments to prove semiconservative mode of chromosome replication on
Correct Answer: (b)
Taylor used radioactive thymidine on Vicia faba (Faba bean) roots.
Q77. Which of the following rRNAs acts as structural RNA as well as ribozyme in bacteria?
Correct Answer: (c)
23S rRNA acts as the peptidyl transferase ribozyme.
Q78. The equivalent of a structural gene is
Correct Answer: (b)
A cistron is the unit of DNA that codes for one polypeptide.
Q79. The ovule of an angiosperm is technically equivalent to
Correct Answer: (a)
The ovule is synonymous with the megasporangium.
Q80. Free-central placentation is found in
Correct Answer: (a)
Dianthus and Primrose exhibit free-central placentation.
Q81. Stirred-tank bioreactors have been designed for
Correct Answer: (c)
The stirrer ensures uniform mixing and aeration.
Q82. Pollination in water hyacinth and water lily is brought about by the agency of
Correct Answer: (b)
Despite being aquatic, these plants use wind or insects because flowers emerge above water level.
Q83. In male cockroaches, sperms are stored in which part of the reproductive system?
Correct Answer: (a)
Sperms are stored in seminal vesicles for maturation.
Q84. The partial pressure of oxygen in the alveoli of the lungs is
Correct Answer: (b)
Alveolar pO2 (~104) is higher than blood pO2 (~40).
Q85. Among the following edible fishes, which one is a marine fish having rich source of omega-3 fatty acids?
Correct Answer: (d)
Mackerel is a fatty sea fish rich in omega-3.
Q86. Select the wrong statement.
Correct Answer: (b)
Pili and fimbriae are involved in attachment; flagella are involved in motility.
Q87. Which of the following is correct for r-selected species?
Correct Answer: (a)
r-strategists maximize reproductive rate with many small offspring.
Q88. Which one of the following generates new genetic combinations leading to variation?
Correct Answer: (c)
Meiosis and fertilization in sexual reproduction lead to recombination and variation.
Q89. Which of the following is correctly matched?
Correct Answer: (c)
Parthenium is an invasive species threatening native biodiversity.
Q90. If '+' sign is assigned to beneficial interaction, '-' sign to detrimental and '0' sign to neutral interaction, then the population interaction represented by '+' '-' refers to
Correct Answer: (d)
Parasitism involves one winner (+) and one loser (-).
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