Regarding assertion and reason, choose the correct statement
Assertion [A]: Marine ecosystems have lesser trophic levels than terrestrial ecosystems.
Reason [R]: Most of the phytoplankton is available for consumption and assimilation by primary consumers in aquatic ecosystems.
Regarding assertion and reason, choose the correct statement
Assertion [A]: Marine ecosystems have lesser trophic levels than terrestrial ecosystems.
Reason [R]: Most of the phytoplankton is available for consumption and assimilation by primary consumers in aquatic ecosystems.
The correct option is D A is false and R is true
In marine ecosystems, phytoplanktons carry out most of the photosynthesis. Phytoplanktons are small organisms like diatoms with extremely simple structures, so most of their primary production or biomass is consumed by primary consumers that feed on them. In contrast, a large fraction of the biomass that land plants produce, such as roots, trunks, are complex and cannot be consumed by herbivores for food, so proportionately less of the energy is fixed from producers to the primary consumers in terrestrial ecosystems. This is the reason why terrestrial ecosystems have smaller food chains or lesser trophic levels than marine ecosystems.
In marine ecosystems, phytoplanktons carry out most of the photosynthesis. Phytoplanktons are small organisms like diatoms with extremely simple structures, so most of their primary production or biomass is consumed by primary consumers that feed on them. In contrast, a large fraction of the biomass that land plants produce, such as roots, trunks, are complex and cannot be consumed by herbivores for food, so proportionately less of the energy is fixed from producers to the primary consumers in terrestrial ecosystems. This is the reason why terrestrial ecosystems have smaller food chains or lesser trophic levels than marine ecosystems.
