Assertion: In an aquatic system, the pyramid of biomass is inverted.
Reason: Biomass depends upon reproductive potential and longevity of individuals.
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 correct but Reason is incorrect
D) Both Assertion and Reason are incorrect

Hint: When the energy transfer takes place in the trophic level, some of it is stored as biomass. Biomass is the energy that is available for the next and the subsequent trophic levels as it can be eaten. During the transfer of the biomass, only 10% is passed from one trophic level to another.

Complete answer:
An Eltonian pyramid or ecological pyramid graphically represents the biomass or bio productivity at each trophic level in a given ecosystem. There are three types of pyramids-
1. The energy pyramid-represents the allocation in the food chain of energy.
2. The pyramid of numbers- is the number of individual organisms in a unit region at each trophic level.
3. The pyramid of biomass-displays the sum of biomass at each trophic level.

Upright Biomass Pyramid: This type of pyramid is typically seen on land with a large base of primary producers and a smaller trophic level at the top.

Inverted Biomass Pyramid: This type is used mainly in aquatic environments. The producers are tiny phytoplankton in a water body that expands in huge amounts. In this, with the producer biomass at the base supplying support to the user biomass at the apex, the foundation is weak. Therefore, an inverted form is desired.

The biomass thus depends on the reproductive ability and the survival of organisms, and the biomass cycle of the aquatic environment is reversed.

The correct option is A, ‘Both assertion and reason are correct and reason is the correct explanation of assertion’.

Note:The cumulative amount of the abundance of benthic organisms and brown algae in the marine environment surpasses that of all producers and consumers. Another example is that of fish, the biomass of which is much greater than that of phytoplanktons. Strong reproductive capacity and brief lifespans of the phytoplanktons.