By David Lin-Cesena 4th BIOLOGY

The first arthropods appeared in the sea more than 600 million years ago.

The evolution of arthropods has led to fewer body segments and highly specialized appendages for feeding, movement, and other functions.

Most living arthropods, such as spiders and insects, have only two or three different forms that have different functions.

Feeding: Arthropods include herbivores, carnivores, and omnivores.

Respiration: Most terrestrial arthropods breathe through a network of branching tracheal tubes that extend throughout the body.

Circulation: Arthropods have an open circulatory system.

Response: Most arthropods have a well-developed nervous system

Movement: Arthropods move using well-developed groups of muscles that are coordinated and controlled by the nervous system.

Exoskeletons do not grow as an organism does.

When they outgrow their exoskeletons, arthropods undergo periods of molting.

During molting, an arthropod sheds its entire exoskeleton and manufactures a larger one to take its place.

To protect themselves, arthropods typically hide during the molting period.

"Arthropod -." Wikipedia, the Free Encyclopedia. Web. 23 Feb. 2010. <http://en.wikipedia.org/wiki/Arthropod>.

"HowStuffWorks Videos "How Termites Work"" Howstuffworks "Video Channel" Web. 31 Mar. 2010. <http://videos.howstuffworks.com/howstuffworks/356-how-termites-work-video.htm>.

"Introduction to the Arthropoda." UCMP - University of California Museum of Paleontology. Web. 23 Feb. 2010. <http://www.ucmp.berkeley.edu/arthropoda/arthropoda.html>.

Miller, Kenneth R., and Joseph S. Levine. Prentice Hall Biology (Student Edition). Upper Saddle River: Pearson Prentice Hall, 2001. Print.

Photograph. Web. <http://bio1152.nicerweb.com/doc/class/bio1152/Locked/media/ch32/32_12CicadaEcdysis.jpg>.

Photograph. Web. <http://evolution.berkeley.edu/evolibrary/images/arthropods_genericancestor.gif>.

Video of Termites