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.

(i) The birth rate in India is very high because most of the rural population which forms the bulk of our society are illiterate, ignorant and superstitious. They are unaware of the need for family planning. Children are considered to be helping hands to increase the family income.

(ii) Haemoglobin has very strong affinity for carbon monoxide, forming a stable compound carboxyhaemoglobin. This cuts down the capacity of blood for transporting oxygen, sometimes resulting in death.

(iii) When excessive fertilizers are added to the moist soil close to the root hair cell, it will form a hypertonic solution as compared to root hair cells. Plasmolysis/exosmosis takes place resulting in the protoplasm to shrink. The plasma membrane withdraws itself from the cell wall. Hence, the root hairs become flaccid and droop.

(iv) Acid rain is harmful to the environment due to the following reasons:

1. It increases the acidity in the soil and destroys forests and crops.
2. It corrodes buildings, monuments, statues, bridges, fences and railings.
3. It poses a serious threat to human health, since it contaminates air and water.
4. Aquatic species are affected due to increased acidity of water in lakes and rivers.
5. It affects plant growth. Plant leaves get burnt and dry.

(v) All life on Earth is supported by Photosynthesis because photosynthesis is ultimately the source of energy and food for all living beings. It is the only biological process which releases oxygen in the atmospehre. Oxygen supports all the life on earth. The starting point of any food chain is always a plant. If green plants were to suddenly disappear, then so would virtually all life on Earth.