Mammals

Definition

Mammals are a class of vertebrate animals characterized by the presence of mammary glands which produce milk to feed their young. They also typically have hair or fur, three middle ear bones, and a neocortex region in the brain.

5 Must Know Facts For Your Next Test

1. Mammals give live birth with few exceptions like monotremes which lay eggs.
2. The mammalian heart is four-chambered, allowing for efficient circulation and oxygenation of blood.
3. Mammals exhibit various types of teeth differentiation including incisors, canines, premolars, and molars.
4. They have endothermic (warm-blooded) metabolisms that regulate internal body temperature.
5. Most mammals have a diaphragm that aids in respiratory efficiency.

Review Questions

Related terms

Monotremes:

Egg-laying mammals such as the platypus and echidna.

Marsupials: A group of mammals primarily known for carrying and nursing their young in pouches, like kangaroos and koalas.

Placental Mammals: Mammals that nourish their unborn young via a placenta during gestation, including humans and most other mammals.