61. Which one from those given below is the period for Mendel's hybridization experiments ?
2.1840 - 1850
3. 1857 - 1869
4.1870 – 1877
62. Good vision depends on adequate intake of carotene rich food.
Select the best option from the following statements.
(a) Vitamin A derivatives are formed from carotene.
(b) The photopigments are embedded in the membrane discs of the inner segment
(c) Retinal is a derivative of Vitamin A.
(d) Retinal is a light absorbing part of all the visual photopigments.
1. (a) and (b)
2. (a), (c) and (d) ,
3. (a) and (c)
4. (b), (c) and (d)
63. Which one of the following statements is not valid for aerosols ?
1. They are harmful to human health
2. They alter rainfall and monsoon patterns
3. They cause increased agricultural productivity
4. They have negative impact on agricultural land
64. A decrease in blood pressue/volume will not cause the release of
2. Atrial Natriuretic Factor
65. Homozygous purelines in cattle can be obtained by:
1. mating of related individuals of same breed.
2. mating of unrelated irdividuals of same breed.
3. mating of individuals of different breed.
4. mating of individuals of different species.
66. The vascular cambium normally gives rise to
2. Primary phloem
3. Secondary xylem
67. Which of the following statement is correct ?
1.The ascending limb of loop of Henle is impermeable to water.
2. The descending limb of loop of Henle is impermeable to water.
3. The ascending limb of loop of Henle is permeable to water.
4. The descending limb of loop of Henle is permeable to electrolytes.
68. Fruit and leaf drop at early stages can be prevented by the application of:
4. Gibberellic acid
69. A baby boy aged two years is admitted to play school and passes through a dental check - up. The dentist observed that the boy had twenty teeth. Which teeth were absent ?
70. An important characteristic that Hemichordates share with Chordates is :
1. absence of notochord
2. ventral tubular nerve cord
3. Pharynx with gill slits
4. pharynx without gill slits
61. 1. 1856-1863
62. 3. (a) and (c)
63. 3. They cause increased agricultural productivity
64. 2. Atrial Natriuretic Factor
65. 2. mating of unrelated irdividuals of same breed.
66. 3. Secondary xylem
67. 1.The ascending limb of loop of Henle is impermeable to water.
68. 4. Gibberellic acid
69. 3. Pre-molars
70. 3. Pharynx with gill slits