71. Which of the following immune responses is responsible for rejection of kidney graft?
(1) Auto-immune response
(2) Humoral immune response
(3) Inflammatory immune response
(4) Cell-mediated immune response
Answer (4) Cell-mediated immune response
72. Use of an artificial kidney during hemodialysis may result in :
(a) Nitrogenous waste build-up in the body
(b) Non-elimination of excess potassium ions
(c) Reduced absorption of calcium ions from gastro-intestinal tract
(d) Reduced RBC production Which of the following options is the most appropriate?
(1) (a) and (b) are correct
(2) (b) and (c) are correct
(3) (c) and (d) are correct
(4) (a) and (d) are correct
Answer (3) (c) and (d) are correct
73. Which of the following statements is correct?
(1) Cornea is an external, transparent and protective proteinacious covering of the eye-ball.
(2) Cornea consists of dense connective tissue of elastin and can repair itself.
(3) Cornea is convex, transparent layer which is highly vascularised.
(4) Cornea consists of dense matrix of collagen and is the most sensitive portion the eye.
Answer :(4) Cornea consists of dense matrix of collagen and is the most sensitive portion the eye.
74. The frequency of recombination between gene pairs on the same chromosome as a measure of the distance between genes was explained by :
(1) T.H. Morgan (2) Gregor J. Mendel (3) Alfred Sturtevant (4) Sutton Boveri
Ans: (3) Alfred Sturtevant
75. Match the following genes of the Lac operon with their respective products : -
(a) i gene (i) galactosidaseb
(b) z gene (ii) Permease
(c) a gene (iii) Repressor
(d) y gene (iv) Transacetylase
Select the correct option.
(a) (b) (c) (d)
(1) (i) (iii) (ii) (iv)
(2) (iii) (i) (ii) (iv)
(3) (iii) (i) (iv) (ii)
(4) (iii) (iv) (i) (ii)
Answer (3) (iii) (i) (iv) (ii)
76. It takes very long time for pineapple plants to produce flowers. Which combination of hormones can be applied to artificially induce flowering in pineapple plants throughout the year to increase yield?
(1) Auxin and Ethylene
(2) Gibberellin and Cytokinin
(3) Gibberellin and Abscisic acid
(4) Cytokinin and Abscisic acid
Answer (1) Auxin and Ethylene
77. Identify the cells whose secretion protects the lining of gastro-intestinal tract from various enzymes.
(1) Chief Cells (2) Goblet Cells (3) Oxyntic Cells (4) Duodenal Cells
Answer : (2) Goblet Cells
78. Which of the following can be used as a biocontrol agent in the treatment of plant disease?
(1) Trichoderma (2) Chlorella (3) Anabaena (4) Lactobacillus
Answer : (1) Trichoderma
79. Phloem in gymnosperms lacks :
(1) Albuminous cells and sieve cells
(2) Sieve tubes only
(3) Companion cells only
(4) Both sieve tubes and companion cells
Answer (4) Both sieve tubes and companion cells
80. Extrusion of second polar body from egg nucleus occurs :
(1) after entry of sperm but before fertilization
(2) after fertilization
(3) before entry of sperm into ovum
(4) simultaneously with first cleavage
Answer (1) after entry of sperm but before fertilization