The chief distinguishing characteristic of all mammals is the presence of
A)constant internal temperature.
B)four limbs.
C)a four-chambered heart.
D)hair and mammary glands.
E)a placenta.

Question

Quizplus · Accepted Answer

While mammals have other unique characteristics such as the presence of a diaphragm and three middle ear bones, the most notable and distinguishing characteristic is the presence of hair and mammary glands for producing milk to nourish their young.

The Chief Distinguishing Characteristic of All Mammals Is the Presence