Bellringer

1. Section 2 Mollusks and Annelid Worms Chapter 15 Bellringer • Unscramble the following words and write a sentence that uses all of the words. • gluss • isalns • sdusqi • klomssul • Write your sentence in yourscience journal.

2. Section 2 Mollusks and Annelid Worms Chapter 15 Objectives • Explain how mollusks eat, control body functions, and circulate blood. • Describe the four body parts that most mollusks have in common. • Describe the three kinds of annelid worms.

3. Section 2 Mollusks and Annelid Worms Chapter 15 Mollusks • Most mollusks fit into three classes: • The gastropods include slugs and snails. • eat with radula, a toungelike organ covered in teeth • The bivalves include clams and other shellfish with two shells. • use gills to filter tiny plants, bacteria, and other particles from the water.

4. Section 2 Mollusks and Annelid Worms Chapter 15 Mollusks, continued • The cephalopods include squids and octopuses. • grab food with tentacles and place it in their powerful jaws

5. Section 2 Mollusks and Annelid Worms Chapter 15 Mollusks, continued • Ganglia and BrainsAll mollusks have complex ganglia. • control breathing, movement, and digestion. • Cephalopods, such as octopuses, have large brains that connect all of their ganglia. • Most advanced nervous system of all invertebrates..

6. Section 2 Mollusks and Annelid Worms Chapter 15 Mollusks, continued • Pumping Blood • open circulatory system, a simple heart pumps blood through blood vessels that empty into sinuses, or spaces in the animal’s body. • Most mollusks have an open circulatory system.

7. closed circulatory system, a heart pumps blood through a network of blood vesselsthat form a closed loop. Squids and octopuses Mollusks Pumping Blood , continued

8. Section 2 Mollusks and Annelid Worms Chapter 15 Mollusks, continued • Mollusk Bodies • Foot – muscular foot for moving • Visceral Mass – gills, gut, and other organs are in visceral mass • Mantle – covers visceral mass and produces shell

9. Chapter 15 Section 2 Mollusks and Annelid Worms

10. Section 2 Mollusks and Annelid Worms Chapter 15 Annelid Worms • bodies have segments. Asegmentis almost an identical, repeating body part. • bilateral symmetry • closed circulatory system • complex nervous system with a brain. • Annelid worms live in salt water, fresh water, or on land. They eat plant material or animals.

11. 3 Major groups Earthworms Marine Worms Leeches Annelid Worms

12. Section 2 Mollusks and Annelid Worms Chapter 15 Annelid Worms, continued • Earthworms • Each earthworm has 100 to 175 segments. • Their castings, or waste, improves soil quality. • Tunnels allow air and water to enter soil • use stiff hairs, or bristles, on the sides of their bodies to move.

13. Section 2 Mollusks and Annelid Worms Chapter 15 Annelid Worms, continued • Marine Worms • Polychaete – many bristles • live in the ocean. • eat mollusks, other small animals, or filter food from the water.

14. Leeches Some leeches are parasites that suck other animals’ blood. Other leeches eat dead animals or hunt insects, slugs, and snails. Secrete a chemical to keep blood flowing and not form clots Used for medical purposes Doctors use leeches to prevent swelling. Annelid Worms, continued