Nematodes (roundworms)


A. Organized Body Made of One or More Cells - Ashley J

Roundworms have a slender tube-like body that is tapered at both ends. The body is like a tube within a tube with fluid in between. Roundworms have two body openings: a mouth and an anus. The anus is an opening at the end of the digestive tract through which wastes leave the body. Examples of roundworms are hookworms, pinworms and whipworms.

The roundworms body structure
The roundworms body structure
A roundworm
A roundworm

B. Obtain and Use Energy - Cole S

Roundworms have a grasping mouth.They have teeth. And a stylet that sucks up liquid. They have enzymes that breakdown food. They eat small animals algae, fungi, bacteria, and decaying organic matter.

(Roundworm in human Colon)

C. Reproduce - Ashley J

A roundworm reproduces sexually and they do mate. The female roundworm lays the eggs either in the hosts body or the soil. The eggs are usally laid in the soil or in the host when it gets in the host's body, such as through touch or if they are eaten. Most nematodes are free-living. Then the eggs hatch into larvae looking identical to the adults.

A nematode and its egg
A nematode and its egg

D. Grow and Develop - Cole S

Females lay eggs and they travel with the feces. Animals eat grass or other foods where the eggs are. The eggs hatch in their body and penatrate the intestinal wall. They go through the wall and to the bloodstream. Then to the liver where the roundworms travel to the heart. After they go to the lungs and finally to the throat where they get swallowed. This journey takes about 10 days. They live in the intestines for about 1 year in their 2 years of life.

E. Respond to Stimuli - William P

Roundworms have several ganglia which connect nerves to the head and length of the body. They have a Dorsal nerve that runs down their back to control all of the muscles. The Lateral nerves are on the worms' sides and transmit sensory information through the body. The ventral nerve controls motor control and sensory input in the body. Soil dwelling worms push through the soil, and water dwelling worms move like a snake. Both are examples of roundworms.

(Video of roundworms' response to touch)

F.Exchange Gases with the Environment - William P

Roundworms exchange gases with the enviroment through their skin. Because Roundworms exchange gases

throught their skin they must stay moist.

Roundworms in a moist area

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2. Miller R., Kenneth; Levine, Joseph, Biology, Upper Saddle River, New Jersey, Pearson Education, 2002

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4. Coolidge-Stoltz, Elizabeth et. al., Life Science, New Jersey, Pearson Education, Inc.,2002

5.Heimler H., Charles, Life Science, Columbus, Ohio, Merrill Publishing Co.,1989

6.Wikipedia. Nematodes.

7.Fleisher, Paul Parasites Latching on to a free lunch, Minnieapolis, Minnisota,Twenty-First Century Book, 2006