Roundworms

Melany Morris

Level Of Organization

They are in the organ-level.


Germ Layers

Roundworms are triploblastic, which means their embryos have all three germ layers.


Symmetry

They have bilateral symmetry.


Cephalization

Yes, They have a head.


Body Cavity

The body cavity is called a pseudocoelom.


Segmentation

Yes, roundworms have segmentation.


Digestive System

Yes they do. They have a mouth and an anus.


Circulatory System

A roundworm has no heart or formal blood vessels.


Respiratory System

A roundworm has no formal respiratory system.


Excretory System

A roundworm has an anus at its rear end and a series of excretory tubes that end in an excretory pore.


Nervous System

A roundworm has two nerve cords that transmit impulses in the roundworm.


Reproduction

A roundworm reproduces sexually. The female has an ovary, holds eggs in an oviduct and then passes them to the uterus, where they are fertilized. The male has sperm cells are made in the testis and stored in the vas deferens. When it is time to reproduce, the sperm cells pass through the spicule. Over 200,000 eggs can be deposited at once in the soil once they are fertilized.


Support

A roundworm has no skeleton.