Define the following :
(i) Food chain,
(ii) Trophic level,
(iii) Producers,
(iv) Parasites.

Explanation

(i) Food chain : Food chain is the sequence of transfers of matter and energy in the form of food from organism to organism.
(ii) Trophic level : Each step or level of the food chain is called trophic level.
(iii) Producers : Producers are organisms like plants and blue green algae that produce complex organic compound from simple inorganic molecules using energy from sunlight in presence of chlorophyll.
(iv) Parasites : An organism that lives on or in another organism, obtain nourishment and protection while offering no benefit in return is called a parasite.