SKELETAL SYSTEM

The skeletal system provides a strong framework to hold a body up, maintain its shape, protect soft organs and provide sites for muscles to attach for movement. There are three skeleton types which are hydrostatic, exoskeleton and endoskeleton.

I think the main advantage of the skeletal system is that it provides protection for our internal organs. It's what helps us move! It supports parts of our bodies. It's our framework.  Advantages of organisms that have a hydrostatic skeleton is that they're very flexible and can squeeze themselves to fit in between spaces and pathways. For animals with exoskeletons, they have shells that provide them protection and support. Their shells are really hard which is beneficial so they won't get crushed easily. 

For hydrostatic skeletons, a disadvantage would be is not being able to lift things. They also don't have protection since they're just made of water and muscles. For exoskeletons, they can't grow much so a limitation on size would be a disadvantage. For endoskeletons, our protection externally would be our skin and our skin isn't hard nor tough like exoskeletons. I think another disadvantage is to fracture a bone. 

Sources: 

http://biology.clc.uc.edu/courses/bio105/bone.htm 

http://www.infovisual.info/02/028_en.html 

http://www.sas.upenn.edu/~rlenet/Earthworms.html

http://www.davidlnelson.md/Cazadero/Crawdad.htm       

http://www.ehow.com/facts_5521715_advantages-disadvantages-hydrostatic-skeleton.html

Holt, Rinehart and Winston Modern Biology

Austin: Holt, Rinehart and Winston, 2002