Which of these pairs of body structures best illustrates a homologous relationship? a) the leg of a horse and the leg of a dog
b) the wing of a bat and the wing of a bird
c) the fin of a dolphin and the fin of a shark
d) the beak of a bird and the beak of a turtle

The correct answer would be A) the leg of a horse and the leg of a dog.

Homologous organs refer to the set of organs which are similar in their structure but performs different functions as a result of adaptation towards different environments.

These organs are the result of divergent evolution.

For example, human arm, horse leg, dog's leg, the wing of a bird, and the flipper of a dolphin or whale are formed from the same set of bones and but perform different functions and thus, they are the homologous organs.