Question

The organisms dwelling at the bottom of a lake are called as
A. Phytoplankton
B. Zooplankton
C. Nektons
D. Benthos

Answer 1

Phytoplankton belong to the Kingdom Protista . Phytoplankton is a unicellular food-producing organism. Zooplankton is also unicellular organisms belonging to the Kingdom Protista.

Complete answer: A number of organisms live in water they are called aquatic organisms.
Various aquatic habitats are such as Marine, pond, lake, and river.
The bottom habitat is called benthic while the above bottom habitat is called a pelagic habitat.
Organisms confined to the bottom are called benthos. In organisms that are pelagic fully differentiated into plankton microscopic drifting work surfaces, neuston macroscopic floating on swimming on or near the water surface, and nektons actively swimming inside water.

Additional Information:
1. Benthos is the community of organisms that live on or near the seabed, river, lake, or stream bottom also known as the benthic zone.
2. This community lives in or near marine or freshwater sedimentary environments from tidal pools along the foreshore, out to the continental shelf, and then down to the depths.

So, the correct answer is “Option D. Benthos ”.

Note: Many organisms adapted to deep-water pressure cannot survive in the upper part of the water column. The pressure difference can be very significant approximately 1 atmosphere for every 10 meters of water depth. Because light is absorbed before it can reach deep ocean water, the source for the benthic ecosystems is often organic matter from higher up in the water column that drifts down to the depths.