Choose the odd one out from the following terms and name the category to which the others belong:
Leaves, Styrofoam, Grass, Cow Dung
Topic: Biodegradable wastes
Answer
Odd one out: STYROFOAM. Category of the others: BIODEGRADABLE WASTES.
Leaves, grass and cow dung are all ORGANIC matter that decomposers — bacteria and fungi — can break down into simple substances that return to the soil. They are BIODEGRADABLE.
STYROFOAM is a synthetic polymer (expanded polystyrene). No organism possesses enzymes capable of digesting it, so it persists in the environment for hundreds of years. It is NON-BIODEGRADABLE.
THE TEST that sorts almost any list of this kind: ask whether the substance was ever ALIVE or came from something alive. Leaves, grass and dung all did; Styrofoam did not.