Which of the following structures is homologous to the wing of a bird?

Solution & Explanation

Answer: (D) Flipper of whale. The wing of a bird and the flipper of a whale are both forelimbs built on the same underlying bone pattern (humerus, radius, ulna, carpals, metacarpals, phalanges); structures with the same anatomical plan inherited from a common ancestor are homologous, regardless of differing function. The moth's wing is an insect structure that only performs a similar function (analogous), the shark's dorsal fin is not a forelimb, and a rabbit's hind limb is a different (posterior) limb. So only the whale flipper is homologous to the bird wing. NCERT Reference: Ch 6 Evolution, p.114, lines 7–13: "share similarities in the pattern of bones of forelimbs ... they have similar anatomical structure – all of them have humerus, radius, ulna, carpals, metacarpals and phalanges in their forelimbs. ... This is divergent evolution and these structures are homologous."