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Assertion: Aquatic herbivores are usuall...

Assertion: Aquatic herbivores are usually more productive as compared to terrestrial herbivores.
Reason: Phytoplanktons achieve faster grwoth rate and more nutritious to heterotrophs than their terrestrial counterparts due to their small size and lack of structural tissues.

A

Both assertion and Reason are correct and Reason is the correct explanation for assertion.

B

Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.

C

Assertion is not correct but Reason is incorrect.

D

Both Assertion and Reason are incorrect.

Text Solution

Verified by Experts

The correct Answer is:
A
Most plant material is not consumed or is not digested by terrestrial herbivores, because plants have so much structural material. Most algal material (phytoplanktons) is consumed and digested by aquatic herbivores, because algae have very little structural material. Moreover, phytoplanktons turn over much more rapidly than terrestrial plants, so biomass at any given time is low as compared to the productivity. Phytoplanktons grow and reproduce rapidly, so a small mass can have a faster rate of primary production. In contrast, terrestrial primary producers grow and reproduce slowly. Thus, terrestrial herbivores are less productive than aquatic herbivores.
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