Wednesday, May 24, 2006

Reptile Podcast


Here is the class’s first attempt at a Podcast. The class had the unique opportunity to Interview World renowned reptile expert form the National Geographic Channel, Dr. Brady Barr. Each group had a set of questions to ask the expert. The interview was then used in a fictitious radio station broadcast. We had allot of fun with the project and want to thank Dr. Brady Barr publicly for offering his time and expertise.

  • Click here to listen to group one's podcast consisting of Nicole, John Amber and Andrew interview Dr. Barr about the "American Crocodile."
  • Click here to listen to group two's podcast consisting of Sheena, Cresheva and Briancca interview Dr. Barr about the "American Alligator".

Thursday, May 04, 2006

26.4 Phylum Nematoda

Phylum Nematoda
*The phylum Nematoda is made up of roundworms with long slender bodies that taper at both ends.
*Roundorms are among several phyla of pseudocoelomates.
*Roundworms have a digestive tract with two openings.
*Most species are free-living; some are parasites.
Ascaris
*The genus Ascaris infects pigs,horses,and humans.
*The eggs enter hosts through contaminated food or water, develope into larvae in the intestines, and can infect the lungs.
*The eggs are spread in the hosts' feces.
Hookworms
*Hookworms are intestinal parasites that feed on blood.
*The eggs produce larvae in soil, and the larvae enter hosts through the feet.
*Hookworms infect about one billion people worldwide.
Trichinella
*The genus Trichinella infects humans and other mammals.
*Adults live in intestines and larvae form cysts in muscles.
*People usually become infected from undercooked pork.
*Infection causes the disease trichinosis.
Other Parasitic Roundworms
*Pinworms, genus Enterobius, are common parasites of humans. They do not cause any serious disease.
*Filarial worms infect many people in tropical countries.
The most dangerous ones infect the lymphatic system and may cause elephantiasis.


THE NEXT BLOGGER WILL BE JE'LISA BAILEY

26.3 Platyhelminthes

Structure and Function of Flatworms
*The phylum Platyhelminthes inclides organisms called flatworms.
*They are more complex than sponges but are the simplest animals with bilateral symmetry.
*They are acoelomates (no body cavity)
*They exhibit cepholization (have a head)
Class Turbellaria-Planarians
Digestive and Excretion in Planarians
*The most familiar turbellarians are the freshwater planarians.
*Planarians feed on decaying plant or animal matter and small organisms.
*Food is ingested through the pharynx
*Planarians eliminate excess water through a network of excretory tubules.
*Each tubule is connected to several flame cells where water is excreted.
Nueral Control in Planarians
*The Planarians nervous system is more complex than the nerve net of cnidarians.
*The cerebral ganglia serveas a simple brain.
*A planarian's nervous system gives it the ability to learn.
*Planarians sense light with eyespots.
*Others sensory cells resoond to touch, water currents, and chemicals in the environment.
Reproduction in Planarians
*Planarians are hermaphrodites that can reproduce sexually or asexually.
*During asexually reproduction, their body undergoes fission and the two halves regenerate missing parts.
Class Trematoda
*The class Trematoda consist of parasistic flukes.
*Some are endoparasites;others are ectoparasites.
Structure of Flukes
*A Fluke clings to the tissue of its host by on anterior sucker and a ventral sucker.
*A Fluke's nervous system is similar to a planarian's but simpler.
Reproduction and Life Cycle of Flukes
*Most Flukes have highly developed reproductive systems and are hermaphroditic.
*Flukes have complicated life cycles the involve more than one host species.
*For example, the trematocle blood flukes of the genus Schistosome use humans as a primary host. They can cause schistosomiasis.
Class Cestoda
*About 5,000 species of tapeworms make up the class cestoda.
*Tapeworms can live in the intestines of almost all vertebrates.
Structure of Tapeworms
*Tapeworms are surrounded by a tegument.
*They attach to the host w/a scoley.
*The body is a series of many.
Sections called proglotius
*Tapeworms have no light-sensing organs,no results,no gastrovascular cavity,and no digestive organs.
Reproduction and Life Cycle of Tapeworms
*Nearly all tapeworms are hermaphrodites.
*New proglottius are added to the front of the tapeworm. Older proglottius grew,mature, and begin producing eggs.
*Eggs in one proglottius,are usually fertilized by sperm from a different proglottius,possibly a different individual.
*An example is the beef tapeworm, Tuenia saginatus. Its primary host is a human and its intermediate host is a cow. Its larvae form cysts in the muscle tissue of the cow.