Driving force of an ecosystem is

In an ecosystem in abiotic components which of the following occur

Transfer of material and energy from one ecosystem to other ecosystem is best examplified by

In pond ecosystem, diatoms represent

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.