Question

Assertion (A): Diapause is a state of suspended development
Reason (R): Many phytoplankton species enter the state of diapause under unfavourable conditions

• A. Both assertion and reason are true and the reason is the correct explanation for the assertion
• B. Both assertion and reason are true but the reason is not the correct explanation for the assertion
• C. Assertion is true but the reason is false
• D. Both assertion and reason are false

Answer 1

The correct option is C Assertion is true but the reason is false

Responses to the changes in abiotic/non-living factors in the environment can be in different forms. If the changes in the external environment are unfavourable but short-lived, then many organisms choose to either move away to a more favourable environment (migrate) or suspend their activities till favourable conditions return.

Diapause is a state of suspended development, in response to unfavourable conditions, which is seen in zooplankton species. This mechanism holds the development of an animal at a particular developmental stage unless the unfavourable conditions pass over. It is marked by reduced metabolic activity.

Hence, the assertion is true but the reason is false.