Question

With regard to the assertion and reason, choose the correct option:
Assertion [A]: Organs can get modified on similar plans of organisation and embryonic development.
Reason [R]: Adaptive radiation results in the development of homologous structures.

• A. Both A and R are correct and R explains A
• B. Both A and R are correct but R does not explain A
• C. A is incorrect but R is correct
• D. Both A and R are incorrect

Answer 1

The correct option is A Both A and R are correct and R explains A

Those organs which have the same embryonic origin and basic structure, and get modified to perform different functions in different species are called homologous organs. Such similarities in the basic morphological structures in the organs are generally referred to as homologies. Species which have diverged from a single original common ancestor, get adapted to new habitats, eventually giving rise to new species. This is called adaptive radiation. Such adaptations involve gradual modification of existing traits according to the new environment, resulting in the development of homologous organs.