Mammals are vertebrates that possess hair and mammary glands, have a middle ear with three bones to hear higher-pitched sounds, and a chewing jaw in order to break up food more quickly.

The Tasmanian devil is one of several marsupials native to Australia. (credit: Wayne McLean)

Modern mammals are divided into three main groups:

Monotremes - egg laying mammals (Duck-billed platypus and Echidna)
Marsupials - give birth to live young that mature inside a pouch (opossum, kangaroo, wombat, and koala)
Eutherians - give birth to live young that have completed fetal development (familiar mammals, and humans)

Complete the tasks on the list below:

Go to this page, http://cnx.org/contents/GFy_h8cu@10.53:p6SM1kkx@5/Mammals, and read the entire page
Use the Glossary at the bottom of the page to help with the vocabulary for this week
Use the Review Questions and Free Response questions to check for understanding

Download for free at http://cnx.org/contents/185cbf87-c72e-48f5-b51e-f14f21b5eabd@10.53