Give suitable biological reasons for the following statements :

(i) The birth rate in India is very high.

(ii) Carbon monoxide is dangerous when inhaled.

(iii) Root hairs become flaccid and droop when excess fertilizers are added to the moist soil around them.

(iv) Acid rain is harmful to the environment.

(v) All life on Earth is supported by Photosynthesis.

Match the items given in Column A with the most appropriate ones in Column B and rewrite the correct matching pairs.

In a human male, a sperm will contain:

1. Both X and Y chromosomes
2. Only Y Chromosomes
3. Only X chromosome
4. Either X or Y Chromosomes

A muscular wall is absent in:

1. Capillary
2. Venule
3. Arteriole
4. Vein