Question

__________ is an inactive phase that some organisms undergo during the winter to escape from the harsh conditions.

• A. Adaptation
• B. Aestivation
• C. Acclimatisation
• D. Hibernation

Answer 1

The correct option is D Hibernation

Organisms response to the changes in abiotic or nonliving factors (temperature, pH) in the environment can vary. Some organisms regulate their internal environment to maintain a stable state whereas some conform to the changes in their external environment.

If the changes in the external environment are unfavourable and localised or short-lived, then many organisms choose alternative ways such as migrating or moving away to a more favourable environment or suspending their activities till favourable conditions returns.

Thus, any attribute of the organism (morphological, physiological or behavioural), that enables the organism to survive and reproduce in its habitat is called adaptation.

• Hibernation is a period of long physical inactivity and reduced metabolic activity that some animals undergo during the winter months. This helps them to evade the harsh cold climate and remain comfortable in their burrows or caves. Bears, bats, squirrels, etc., are some organisms which exhibit hibernation. Hence option b is correct.

Figure : Hibernation

• Aestivation is a period of suspended metabolic activities during the summer months and is seen in animals, live in hot and dry habitats to avoid damage by excessive heat and desiccation (drying up). Examples include crocodiles, salamanders, some land snails, lady beetles, etc.

Acclimatisation is an anatomical or physiological response shown by the animal to a specific stress (climate, temperature) in the environment. For example, the low pressure of oxygen (hypoxia) in high mountains results in increasing the number of red blood cells in human beings.