Answer: Vestigial parts
Explanation:
Vestigial parts are body parts seen as useful in some species, while of no use in others.
The human appendix is an example of vestigial parts, because its absence is of no consequence; whereas it plays the role of caecum in herbivores like goat.
Other vestigial parts in humans include the rudimentary mammary glands in man, whereas well developed and functional in woman.
