Question

Which of these statements BEST defines vestigial organs?

a. vital organs that are functional in all organisms of a lineage
b. vital organs that are functional only in alternate generations of a lineage
c. redundant organs present in an organism, which have been functional in the organism’s ancestors
d. redundant organs present in an organism, which will be functional in the succeeding generations of the lineage

Answer 1

The correct answer is c. redundant organs present in an organism, which have been functional in the organism’s ancestors.

Vestigial organ are those which are retained in the evolution however lost their original functions due to change living habits or surroundings of the organisms.

They serve as the evidence of evolution and help in evolutionary studies.

For example, vermiform appendix, nictating membrane of eye, ear muscle etc are vestigial organs found in humans.

Answer 2

The definition of vestigial organs are rudimentary structures in humans that correspond to a functional structure or organ in an ancestor. Basically the answer is redundant organs present in an organism, which have been functional in the organism's ancestors.