What is the role of decomposers in an ecosystem?

Which one of the following is an artificial ecosystem?

Define a food web. State its significance for an ecosystem.

The structural and functional unit of the environment is known as $......$

Select the mismatched pair in the following and correct it.
$(a)$ Biomagnification — Accumulation of chemicals at the successive trophic levels of a food chain
$(b)$ Ecosystem — Biotic components of environment
$(c)$ Aquarium — $A$ man-made ecosystem
$(d)$ Parasites — Organisms which obtain food from other living organisms

Which organisms obtain nutrition from the dead bodies of plants and animals?