| A | B |
|---|
| molting | the periodic shedding and replacing of the old outgrown body covering, such as skin or an exoskeleton |
| molluck | o soft-bodied invertebrate that usually has a hard shell, such as a snail |
| appendage | a structure growing form the body, such as an arm or leg |
| arthropoda | largest animal phylum, classified by the number of body segements and appendages; includes insects, shrimp, spiders, and centepides |
| closed circulatory system | a type of blood-circulation system in which vessels transport blood to the internal organs, as in humans |
| crop | in an earthworm, a sac in the digestive system that stores soil eaten by the worm |
| open circulatory system | a type of blood-circulation system that lacks vessels but instead bathes internal organs in blood, such as in mollusks |
| pesticide | a chemical that kills undesirable plants or animal pests |
| radula | in gastropods, a toungelike organ with rows of teeth that scrape and tear food |
| setea | in a segemented worm, bristle-like structures on the outside of the body that help it grip soil and move |
| tube feet | in echinoderms, the structures connected to the water-vascular system that help them move and feed |
| spiracle | in an arthropod, openings in the abdomen and thorax through which air enters and waste gases leave |
| water-vascular system | in echinoderms, the network of water-filled cannals to which thousands od tube feety are connected |
| ehcinoderm | a spiny-skinned invertebrate that lives in the bottom of the ocean and that moves by means of a water-vascular system |
| exoskeleton | on all arthropods, the hard, lgithweight external covering that shields, supports, and protects the body |
| gill | rogan that exchanges carbon dioxide with water |
| gizzard | in an earthworm, a miscular digestive structure that grinds soil |
| mantle | in a mollusk, the thin layer of tissue that cover the soft body; it secretes chemicals that become a shell or protects the body if no shell exists |
| metamorphis | the changes in body from during the life cycle for example: egg, larva, pupa, adult |
