Question | Answer |
What are the 3 characteristics of Annelids? | they have little rings, they have tube shaped bodies that are divided into many segments, & they have setae bristle like
structures on the outside of each body segment. |
What are some characteristics of segmented worms? | they have bilateral symmetry, a body cavity that
holds organs 2 body openings which are a mouth &
anus, they can live in freshwater, salt water, & moist soil |
How do worms digest and excrete their food? | It takes soil into it's mouth, then the soil goes into the crop. Then the gizzard grinds the soil into bits of organic matter. this matter passes to the intestines where it is broken down & the nutrients are absorbed by the blood & leave through the anus. |
What is a crop? | a sac used for storage. |
What is a gizzard? | a muscular structure which grinds the soil into bits of organic matter. |
Describe the circulation. | They have a closed circulatory system with 2 blood vessels; one along the top and one along the bottom & they meet in front. They have 5 heart-like "aortic arches." these pump blood. They also have smaller vessels that go into each body segment. |
Describe the respiration process. | They have no gills or lungs, so oxygen and carbon dioxide exchange through their skin. |
Describe the nerve response. | Earthworms have a small brain in their front segment. Nerves in each segment join to form the main nerve cord that connects to the brain. |
What do they respond to? | light, temperature, and moisture. |
Describe their reproduction. | Earthworms are hermaphrodites, so like the sponge it makes both sperm and eggs, but it can't fertilize it's own eggs. It has to receive sperm from another earthworm to reproduce. |