Worms and Mollusks (pp. 424 432) This section tells about the characteristics of the three main groups of worms and the main characteristics of mollusks. Use Target Reading Skills As you read, take notes on the main ideas in the section and the important details that support each main idea. Think about the Key Concepts and Key Terms. Use the graphic organizer below to help you take notes. Worms and Mollusks Questions Notes What are the characteristics of worms? Worms are... Characteristics of Worms (pp. 424 425) 1. What are the three major phyla of worms? 2. List five characteristics shared by all worms. a. b. c. d. e. 203
Worms and Mollusks (continued) 3. Circle the letter of each sentence that is true about worms. a. Worms do not have brains. b. A worm has sense organs in its head end to respond to food, mates, and predators. c. Worms can only reproduce sexually. d. In some worm species, each individual has both male and female sex organs. Flatworms (pp. 426 427) 4. Circle the letter of each characteristic of most flatworms. a. flat bodies b. round bodies c. include tapeworms and planarians d. one-way digestive system 5. An organism that lives inside or on another organism and takes its food from that organism is a(n). 6. Circle the letter of each characteristic of planarians. a. parasite b. scavenger c. herbivore d. predator 7. Describe how a planarian feeds. 8. Is the following sentence true or false? Planarians rely on their eyesight to find food. 9. What is a tapeworm? 204
Roundworms (p. 428) 10. Circle the letter of each sentence that is true about roundworms. a. Roundworms can live in nearly any dry environment. b. Roundworms have flat bodies. c. Most roundworms are tiny and hard to see. d. Roundworms have a digestive system that is like a tube, open at both ends. 11. Wastes exit a roundworm s digestive system through an opening called the. 12. What is the advantage of a one-way digestive system? Segmented Worms (p. 429) 13. Circle the letter of each sentence that is true about segmented worms. a. Segmented worms have an open circulatory system. b. Earthworms are a type of segmented worm. c. Segmented worms have bodies made up of many linked sections. d. Reproductive organs are found in every segment of an earthworm. 14. Earthworms have a digestive system with opening(s). 15. What is the advantage of a closed circulatory system? 205
Worms and Mollusks (continued) Characteristics of Mollusks (p. 430) 16. Circle the letter of each characteristic of a mollusk. a. vertebrate b. invertebrate c. segmented body d. unsegmented body 17. Give the function of each of the following parts of a mollusk. hard outer shell: mantle: foot: 18. Is the following sentence true or false? Mollusks are found only in dry places on land. 19. What is an open circulatory system? 20. What are the functions of gills and the cilia on the gills? Diversity of Mollusks (pp. 431 432) 21. List the characteristics that biologists use to classify mollusks. a. b. c. 206
22. Complete the concept map to show the three major groups of mollusks. Mollusks are classified as 23. Mollusks that have a single shell or no shell at all are called. 24. What is a radula?. 25. What are bivalves? 26. How are bivalves different from other mollusks? 27. Circle the letter of each sentence that is true about bivalves. a. Bivalves have two shells. b. Bivalves live on land. c. Clams are bivalves. 207
Worms and Mollusks (continued) 28. Mollusks whose feet are adapted to form tentacles around their mouths are. 29. How do cephalopods find and capture food? 30. Circle the letter of each sentence that is true about cephalopods. a. Cephalopods have large eyes and a complex nervous system. b. Cephalopods cannot remember things. c. Cephalopods have closed circulatory systems. d. Cephalopods live in the ocean. 208