Question

Mention peculiar features of class Mammalia.

• A. Endothermic and with a high rate of metabolism
• B. The mammary glands produce milk that nourishes the young
• C. Hair helps insulate the body and maintain a warm, constant body temperature
• D. All of the above

Answer 1

Answer: (D)

All of the above

The characteristics of Mammalia are given below:

1) Warm-blooded.

2) Possess hair which is made of keratin. The evolution of mammalian keratin is believed to be independent of reptilian keratin. Hair provides insulation.

3) Endothermic. The majority of the heat energy is used to maintain their high body temperature

4) Four chambered heart.

5) Mammary glands are used to produce milk to nourish their young. Female glands are the only functional glands.

6) The diaphragm is a muscle that separates the thoracic cavity from the abdominal cavity.

Thus, the correct answer is option D.