Anup participated in a marathon race and felt dehydrated by the end of the race. The human body has mechanisms to conserve water and prevent dehydration. Which part of the nephron is primarily responsible for the reabsorption of water to prevent dehydration?

1. Glomerulus
2. Proximal Convoluted Tubule
3. Loop of Henle
4. Distal Convoluted Tubule

(a) 3

(b) 2 and 3

(c) 1, 2 and 3

(d) 2, 3 and 4

Which of the following process occurs only in meiosis and NOT in mitosis:

1. Chromosome duplication
2. Crossing over
3. Cytokinesis
4. Chromosome alignment

Which adaptation is NOT associated with desert plants to minimise water loss through transpiration?

1. Reduced number of stomata
2. Thick, waxy cuticle
3. Deep root systems
4. Increased leaf surface area

Assertion (A): Spraying of pesticides and insecticides can cause water pollution.

Reason (R): Pesticides and insecticides are non-biodegradable agricultural wastes.

1. (A) is true and (R) is false.
2. (A) is false and (R) is true.
3. Both (A) and (R) are true.
4. Both (A) and (R) are false.