MammalsMammalsNancy ChavezNancy ChavezHaley BairdHaley Baird

Rosario GarciaRosario GarciaBiology 3*Biology 3*

Mammal CharacteristicsMammal Characteristics

All mammals are All mammals are characterized by two characterized by two features: hair and features: hair and mammary glands.mammary glands.

Other mammal Other mammal characteristics; all characteristics; all mammals breath air, mammals breath air, have four chambered have four chambered hearts, and are hearts, and are endotherms that endotherms that generate their body generate their body heat internally.heat internally.

Mammals and Evolution Mammals and Evolution

The first true mammals The first true mammals appeared during the late appeared during the late Triassic Period, about 220 Triassic Period, about 220 million years ago. million years ago.

Example: Tree shrew Example: Tree shrew

Homeostasis Homeostasis Mammals use there Mammals use there

sweat glands to cool sweat glands to cool their bodies. their bodies.

When the sweat from When the sweat from these glands these glands evaporates from the evaporates from the skin, body temperature skin, body temperature is lowered. is lowered.

Mammals that lack Mammals that lack these glands pant to these glands pant to get rid of the excess get rid of the excess heat. Example: Wolf.heat. Example: Wolf.

Work CitedWork Cited Photograph. Web. Photograph. Web.

<http://bayimages.net/pictures/animals/mammals/>. <http://bayimages.net/pictures/animals/mammals/>.

UN-CLIMATE-CANADA-ENVIRONMENT-POLAR BEARSUN-CLIMATE-CANADA-ENVIRONMENT-POLAR BEARS. Photograph. . Photograph. Web. <http://www.elibrary.com/elibweb/elib/do/document?Web. <http://www.elibrary.com/elibweb/elib/do/document?urn=urn:bigchalk:US;BCLib;document;173705825>. urn=urn:bigchalk:US;BCLib;document;173705825>.

Photograph. Web. Photograph. Web. <http://www.encyclopedia.com/topic/tree_shrew.aspx>. <http://www.encyclopedia.com/topic/tree_shrew.aspx>.

A Wolf Stands in the Snow in Their Enclosure in the Zoo in A Wolf Stands in the Snow in Their Enclosure in the Zoo in Worms...Worms... 2010. Photograph. Web. 2010. Photograph. Web. <http://www.elibrary.com/elibweb/elib/do/document?<http://www.elibrary.com/elibweb/elib/do/document?set=search&groupid=1&requestid=lib_standard&resultid=7&editiset=search&groupid=1&requestid=lib_standard&resultid=7&edition=&ts=DBCC62B831FA12D537E0286456324F5C_126825709437on=&ts=DBCC62B831FA12D537E0286456324F5C_1268257094373&start=1&publicationId=&urn=urn%3Abigchalk%3AUS%3BBCLib3&start=1&publicationId=&urn=urn%3Abigchalk%3AUS%3BBCLib%3Bdocument%3B175539296> %3Bdocument%3B175539296>

Miller, Kenneth R., and Joseph S. Levine. Miller, Kenneth R., and Joseph S. Levine. Prentice Hall Biology.Prentice Hall Biology. Upper Saddle River, N.J.: Pearson/Prentice Hall, 2008. Print.Upper Saddle River, N.J.: Pearson/Prentice Hall, 2008. Print.