Question

Second most important trophic level in a lake is
(a) Zooplankton
(b) Phytoplankton
(c) Benthos
(d) None of the above

Answer 1

These are heterotrophic (can’t produce its food) that range from microscopic organisms to large species. They are found on surfaces of large water bodies including oceans and freshwater.

Complete step-by-step answer:
The second most important trophic level in a lake is zooplankton. In the aquatic ecosystem, the ecological pyramid starts with the primary producers which are mainly the phytoplankton such as algae, bacteria, etc. are at the base. Then comes first-order consumers or primary consumers such as zooplankton (also this level includes certain fish) that feed upon phytoplankton, then the small fish, then larger fish such as sharks (carnivores). Benthos occupies higher trophic levels. Zooplanktons occupy the second trophic level as they feed on primary producers. They feed on bacterioplankton, phytoplankton, other zooplankton, etc.

Additional Information:

-Phytoplankton - microscopic marine algae and a key part of the oceans. They provide food for a wide range of sea creatures including whales, snails, and jellyfish. Phytoplankton comes from the Greek word “plant” for ‘Phyto’ and “wanderer” or “drifter” for ‘plankton’.
-Benthos (benthic zone)- is the organisms that live on or near the seabed, lake, or stream bottom. They link primary producers i.e phytoplankton, with higher levels in the food web.
So, the correct answer is ‘Zooplankton’.

Note: An ecological pyramid is a graphical representation to show the relationship between different organisms in a food chain and each of the bars that make up the pyramid represents a different trophic level.