Identify the ODD term in each set and name the CATEGORY to which the remaining three belong. Example: glucose, starch, cellulose, calcium — Odd term: calcium; Category: the others are different types of carbohydrates.
Polythene bag, Crop residue, Animal waste, Decaying vegetable.
Topic: Biodegradable wastes
Answer
Odd term: POLYTHENE BAG. Category of the others: BIODEGRADABLE WASTES.
Crop residue, animal waste and decaying vegetable matter are all BIODEGRADABLE — organic material that decomposers (bacteria and fungi) can break down into simple substances returned to the soil.
A POLYTHENE BAG is a synthetic polymer. No organism possesses enzymes capable of digesting it, so it persists in the environment for hundreds of years.
THE TEST that sorts almost any such list: ask whether the substance was ever ALIVE, or came from something alive. Crop residue, animal waste and vegetables all were; polythene was not.