Saprotrophs grow on:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → Dead organic matter
Saprotrophs are the decomposers of an ecosystem, mainly fungi and bacteria. They get their energy and nutrients by breaking down dead organic matter (detritus). They secrete digestive enzymes that change dead and waste material into simple inorganic substances, and then absorb what they need.
(1) Heavy metal compounds — Incorrect. These are not a food source. Saprotrophs need organic matter for energy.
(2) Dead inorganic complex compounds — Incorrect. Saprotrophs feed on organic matter. Inorganic substances are what they release at the end of decomposition.
(3) Organic materials from living organisms — Incorrect. Taking food from a living host is the habit of a parasite. Saprotrophs feed on dead matter.
(4) Dead organic matter — Correct. This is the detritus on which saprotrophs live and grow.
NCERT Extract:
Energy Flow –
