Assertion: Only red algae are able to flourish at the great dpth of sea.
Reason: Red algae has the pigments r-phycoerythrin and r-phycocyanin.

Options

A. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
B. If both assertion and reason are true but the reason is not a correct explanation of the assertion
C. If the assertion is true but the reason is false
D. If both the assertion and reason are false

Answer

a

Explanation

The red algae flourish and occur in abundance at great depths of sea where other plants do not occur in abundance. The sunlight as it penetrates water. Portions of spectrum such as red. Orange, yellow and green light rays which are of short wavelenghts are filtered out. Only the blue and violet rays of great wavelenght and the green plants are thus unable to carry the red pigment r-phycoreythrin. On the other hand the pigment `gamma-`phycocyanin which are characteristic pigments of all the red algae, can utilize wavelenghts of light (blue and violet rays) not absorbed b chlorophyll.