The mammal heart has how many chambers?

Bats are classified in order

The length of time that mammalian young spend developing in the female reproductive tract is called the

The major excretory product of most mammals is

_____________ is a period of winter-long inactivity in which the hypothalamus of the brain slow metabolic, heart, and respiratory rates.

Animals that feed primarily on arthropods and other soft-bodied invertebrates are called

____________ glands are functional in female mammals and are present, but nonfunctional, in males.

Opossums belong to the group of mammals known as

The __________-, or "wishbone" of a bird is formed from the paired clavicles.

Specialized guard hairs called __________ occur around the nose, eyes, and mouth of many mammals, these hairs are extremely sensitive to displacement.

In rodents, the teeth known as ________grow throughout life and have enamel only on their front surfaces.