Question

Which of the following parts of the bird is modified as wings?
(A) Breast bones
(B) Forelimbs
(C) Hindlimbs
(D) All of these above

Answer 1

Hint: The bird's wing is a paired forelimb in birds. The wings give the birds the power to fly, creating a lift. Terrestrial flightless birds have diminished wings or none in the least (for example, moa). In oceanic flightless birds (penguins), wings can operate as flippers.

Complete answer: The forelimbs of the birds resemble the forearms of humans. The forelimbs constitute the radius and the humerus bones which fused. The forelimbs are modified as wings to assist in their flight. A bird’s wings are its forelimbs. It’s just that simple. Distinguished to mammals and many reptiles, they have lost several bones through fusion and reduction in the course of their evolution, down to only three digits from the ancestral five, for instance. But their wing has a humerus, a radius, an ulna, carpals, metacarpals, and phalanges, just as we do in our forelimbs.
Thus, the correct answer is option B- Forelimbs.

Note: Aves are popularly recognized as "Glorified Reptiles" in whom the forelimbs are adapted to give rise to wings that benefit the flight in them. Bird wings also originate from the forelimbs and are homologous to the human arm, but rather than extended fingers, birds have atrophied hands with only two fingers, one of them vastly diminished.