The incorrect pair is (b) “Ecosystem — Biotic components of environment” because an ecosystem includes both biotic (living) components and abiotic (non-living) components.
Corrected version: Ecosystem — A system composed of living organisms and their physical environment.
Explanation:
Biomagnification:
This definition is correct, as it describes the process where harmful chemicals accumulate in higher concentrations at each trophic level of a food chain.
Aquarium:
This is also a correct definition, as an aquarium is a man-made environment designed to simulate a natural ecosystem.
Parasites:
This definition is correct, as parasites are organisms that live on or within a host organism and obtain nutrients at the host’s expense.