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In this tutorial you model the inside of an earthworm and show how it digests its food. Earthworms belong to the phylum of annelids, class Oligiochaeta. The annelids are segmented worms and in earthworms these segments are externally visible. They have a series of doughnut shaped hearts to pump blood and a long tubular digestive tract. They eat decaying organic material in the soil by ingesting it absorbing the nutrients and releasing the rest as castings. This is very helpful to agriculture as it improves the soil structure by making it more permeable to air and water. Earthworms move by stretching out and anchoring tiny bristles in the soil. Then they pull their tails toward their head ends. Level: Beginning to Intermediate © 2000 Michele Matossian |
