The aquatic organism that can actively swim at will against the water current is

Choose incorrect option w.r.t. amount of living material present in different trophic levels at a given time

In a pond ecosystem, benthos means

Driving force of an ecosystem is

The planktonic forms are

Choose correct answer.

$(1)$ Zooplanktons are primary producers in an aquatic ecosystem.

$(2)$ Decomposition is largely an oxygen requiring process.

$(3)$ In a natural ecosystem, fishes, wolf, etc. are carnivore.

$(4)$ The amount of energy decreases in each successive trophic level.