Mollusks, Worms, Arthropods, Echinoderms

Crossword Puzzle Exercise
Content © 2006 Debbie Smith; Author of Activity: Tami Maloney; All rights reserved. No commercial, for-profit use of this material is allowed. E-mail comments and questions to Tami Maloney.

Complete the crossword, then click on "Check" to check your answer. Click on a number in the grid to see the clue or clues for that number.
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5     6             


1. Organ that exchanges oxygen and carbon dioxide with water
3. A thick layer of tissue that secretes the shell
4. Bristlelike structures that help segmented worms move
5. Structure that grows out from a body, like a leg or antenna
7. Air opening in the abdomen of arthropods
9. Act like strong suction cups and help the animal move, feed, get oxygen, and dispose of water
10. Tongue-like structure in gastropods that works like a file
12. Changes some animals go through to become adults
13. Circulatory system in which blood is not in vessels but spreads over organs


1. Muscular structure in earthworms that grind soil
2. Circulatory system in which blood is contained in vessels
6. Outer covering on arthropods
8. Shedding of the exoskeleton
11. Food storage sac in segmented worms