Match Column I with Column II: Column I Column II A. Ectoparasites 1.…

The correct answer is Option (3) → A-4, B-3, C-2, D-1

(A) Ectoparasites — this matches (4) Lice on humans. Ectoparasites feed on the outer surface of their host. Lice on humans and ticks on dogs are the most familiar examples.

(B) Crow and cuckoo — this matches (3) Brood parasitism. The cuckoo (koel) lays its eggs in the crow’s nest and lets the crow hatch them. Its eggs have come to look like the crow’s eggs, so the crow does not throw them out.

(C) Parasitic plant — this matches (2) Cuscuta. Cuscuta grows on hedge plants. It has lost its chlorophyll and leaves and takes all its food from the host plant.

(D) Marine ectoparasites — this matches (1) Copepods on fish. Many marine fish carry ectoparasitic copepods, small crustaceans attached to the outside of the fish.

NCERT Extract:
Population Interactions – “… Parasites that feed on the external surface of the host organism are called ectoparasites. The most familiar examples of this group are the lice on humans and ticks on dogs. Many marine fish are infested with ectoparasitic copepods. Cuscuta, a parasitic plant that is commonly found growing on hedge plants, has lost its chlorophyll and leaves in the course of evolution.”
Population Interactions – “… Brood parasitism in birds is a fascinating example of parasitism in which the parasitic bird lays its eggs in the nest of its host and lets the host incubate them. … Try to follow the movements of the cuckoo (koel) and the crow in your neighborhood park during the breeding season (spring to summer) and watch brood parasitism in action.”