- http://animaldiversity.ummz.umich.edu/site/accounts/information/Platyhelminthes.
html - http://www.ucmp.berkeley.edu/platyhelminthes/platyhelminthtml
- http://www.ucmp.berkeley.edu/phyla/ecdysozoa/nematoda.html
- http://www.ucmp.berkeley.edu/annelida/annelida.html
- http://animaldiversity.ummz.umich.edu
- http://en.wikipedia.org/wiki/Annelida
Vocabulary
annelida Invertebrate worms that have segmented bodies, such as earthworms.
cephalization Having a head region with a concentration of sensory organs and central
nervous system.
complete digestive tract A digestive tract with two openings, a mouth and anus.
gastrovascular cavity A large cavity having both digestive and circulatory functions.
hydroskeleton Fluid-filled body cavity that provides support for muscle contraction.
incomplete digestive system A digestive tract with only one opening.
nematoda Invertebrate worms that include the roundworms.
platyhelmenthes Invertebrate worms that include the flatworms and tapeworms.
segmentation A body plan that has repeated units or segments.
tapeworms Intestinal parasites in the phylum Platyhelmenthes.
Points to Consider
- How might the vertebrates be different from the invertebrates?
- Can you think of some examples of animals with a backbone?