The structure absent in a nerve cell is:

1. Nucleus
2. Centrosome
3. Cytoplasm
4. Neurilemma

The number of chromosomes in the somatic cells of a human body before mitosis and after mitosis is:

1. 23, 23
2. 26, 46
3. 23, 46
4. 46, 46

Assertion (A): Darwin preferred pea plants for his experiments on genetics as it is a unisexual plant.

Reason (R): Pea plants are normally self-pollinated.

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.

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