Question

Explain any two alternatives by which organisms can overcome stressful external conditions.

Answer 1

The alternatives by which organisms can overcome stressful external conditions are:

(i) Migrate: Some organisms migrate temporarily from an unfavourable habitat to a more favourable habitat and return when the favourable period is over. Example: Migratory birds move from very cold northern regions to warmer places.

(ii) Suspend: Some organisms avoid the unfavourable environment by escaping from it. Example: Polar bears hibernate during winter to escape extreme cold. Some snails and fish undergo aestivation to avoid summer-related problems such as heat and desiccation.