Question

Homologous organs have –
A) Same origin, different function
B) Different origin but same function
C) Same origin same function
D) Different origin and different function

Answer 1

Evolution is unrolling or unfolding of nature that brings about an orderly change from one form or condition to another, resulting in descendants becoming different from ancestors. Evidence supporting evolution are - homologous organs, analogous organs, vestigial organs, and paleontological evidence.

Complete answer:

Option A: Homology is the similarity between organs of different animals based on common ancestry or common embryonic origin. Therefore, this is the correct option.
Example – forelimbs of birds, bats, house, frog and human have the same basic anatomy but they all perform different functions according to their needs. The hopping legs of the frog contain the same bones as our legs, but frog legs are modified for hopping.
Option B: Organs with different origins but same function are known as analogous organs and not homologous organs. Therefore, this is the incorrect option.
Option C and D: These options are irrelevant, therefore, this is the incorrect option.

Thus, the correct answer is option (A) Same origin, different function.

Note: Homology provides evidence for evolution as it indicates common ancestry and divergent evolution. In developmental biology, organs are developed in the embryo in the same manner. Other examples of homologous organs are –

Tailbones of human beings and the tail of a monkey.
Pelvis of a dog, of a cat and of a human and of a snake are homologous structures.
Forelimbs of frog, bird, rabbit and lizard look very different as they are modified according to different needs but have common anatomy.