Download Worksheet 13

Worksheet 13-1 Mollusks
Name _____________________________
HR __________
Score ________/23____
1. Mollusks are soft-bodied ____invertebrates ______________________.
2. Mollusks have _____bilateral _________________________ symmetry.
3. Mollusks usually have _one_________ or _____two____________ shells.
4. The word Mollusk comes from the Latin word meaning ____soft______________________.
5. Most Mollusks live in __water__________ but some live on _____land________________.
6. Give me 3 examples of Mollusks:
A. snails
B. clams
C. squid
7. How many mollusk species have been identified?
110,000
8. Define “Mantle”:
A thin layer of tissue that covers a Mollusks body organs. It secretes the shell or protects the body
without a shell.
9. Where is the body organs located in a Mollusk? Visceral mass
10. What are gills?
Organs that exchange carbon dioxide for oxygen in the water.
11. What secretes the shell of Mollusks?
Mantle
12. Define “open circulatory system”:
Blood circulation system in which blood moves through vessels and into open spaces around body
organs.
13. What are the three most important groups of Mollusks?
A. Gastropods
B. Bivalves
C. Cephalopods
14. What is the largest group of Mollusks?
Gastropods
15. What is a radula?
tongue-like organ with rows of teeth used to scrape and tear food.
16. Name 2 mollusks that live on land:
A. snail
B. Slug
17. Mollusks that have a hinged two part __shell________________ joined by strong muscles are
called ______bivalves______________________.
18. Name 3 bivalves:
A. Clams
B. Oysters
C. Scallops
19. The most complex mollusks are the ___cephalopods______________________.
20. Name 3 cephalopods:
A. Squid
B. Octopuses
C. Cuttlefish
21. Define “closed circulatory system”:
blood circulation in which blood moves through the body in a closed loop or vessels.
22. Mollusk fossils date back more than _____500___________________mya.
23. Are there any mollusks that people like to eat?
yes