1. UNIT 7 WORMS AND MOLLUSCS

2. The animal kingdom: Invertebrates
1.- Invertebrate animals 2.- Porifera and Cnidaria. Page Platyhelminthes, nematodes and annelids 4.- Molluscs 5.- Arthropods 6.- Echinoderms 7.- The importance of invertebrate animals

4. WORMS. Main characteristics:

5. Flat worms

6. Hook worms

7. Ringed worms

8. MOLLUSCS. Main characteristics

15. Bivalves

19. Activities Page 109
3. The snail uses its foot to movement and it also contains the stomach.
The mussel uses its foot to bury itself in the sand and move.
The squid has tentacles which hold and paralyse prey.
The term gastropod means that the stomach is in its foot.
The term bivalve indicates that the animal has a shell formed of two equal parts.
The term cephalopod tells us that the tentacles formed from the foot are attached to the head.
5. It is not a true skeleton because it does not enable movement. The shell has a protective function.