question_answer

Explain the cause of algal bloom in a water body. How does it affect an ecosystem?

OR

Define the terms.

(i) Adaptation

(ii) Alien's rule.

(iii) Commensalism

 

Answer:

Increased concentrations of phosphates and nitrates from industries, residential wastes as well as from agricultural runoff water into the water bodies result in excessive growth of algae which form a mat on the surface of water. This phenomenon is called algal bloom or eutrophication. It affects the ecosystem in following ways:

(a) It decreases light penetration thus affecting photosynthesis.

(b) It results in depletion of dissolved oxygen resulting in death of aquatic life.

(c) Nitrates contaminate drinking water leading to decrease in oxygen carrying capacity of haemoglobin in human beings.

OR

(i)  Adaptations are the morphological, physiological or behavioural attributes that enable the organisms to survive and reproduce in their habitat.

(ii) According to Alien's rule, "mammals from colder climatic region generally have shorter ears and limbs to minimise heat loss".

(iii) Commensalism is the relationship which is beneficial for only one species and the other is neither benefitted nor harmed.