Which of the following features distinguish mammals from other vertebrates ?
A. Hairy skin and oviparity
B. Hairy skin and mammary glands
C. Mammary glands and teeth
D. Pinna and teeth
Correct Answer :
B. Hairy skin and mammary glands
The most unique mammalian characteristic is the presence of milk producing glands (mammary glands) by which the young ones are nourished. The skin of mammals is unique in possessing hair.