What are homologous organs ? Give two examples.

Answer: Organs that have the same basic structure and origin but perform different functions are called homologous organs.

Examples: (1) the forelimb of a human (for holding), the flipper of a whale (for swimming), the wing of a bat (for flying) and the foreleg of a horse (for running) all have the same pattern of bones — humerus, radius-ulna, carpals, metacarpals and phalanges. (2) The thorn of Bougainvillea and the tendril of a gourd plant both develop from the axillary bud. Homologous organs show that these organisms evolved from a common ancestor; they are a morphological evidence of evolution.