Chapter 27 Review Mollusks and Annelids

1. Chapter 27 ReviewMollusks and Annelids Charles Page High School Dr. Stephen L. Cotton

2. Chapter 27 ReviewMollusks and Annelids • The gills of a clam are located in the mantle • The shell of a mollusk consists of calcium carbonate produced by glands in the mantle • Mollusks that are carnivorous drill through the shells of other animals by means of the radula

3. Chapter 27 ReviewMollusks and Annelids • In oysters, the mixture of food and mucus is moved to the mouth by cilia on gills • What type of circulatory system does an oyster have? open • Land snails and slugs breathe by means of specially adapted mantle cavity

4. Chapter 27 ReviewMollusks and Annelids • Compared with other mollusks, the cephalopods have more complex brains. • In a cephalopod, the foot is divided into tentacles • The land slug is believed to have evolved from a shelled ancestor

5. Chapter 27 ReviewMollusks and Annelids • The group of bivalves that burrow into sand and mud includes the clam • Adult bivalves that can move around by flapping their shells are scallops • Nautiluses remain upright and float in water by means of gases

6. Chapter 27 ReviewMollusks and Annelids • The “termites of the sea” are actually shipworms • Mollusks are, or have been, used for food, medicine, environmental indicators, money • What is the first organ through which food travels in an earthworm? pharynx

7. Chapter 27 ReviewMollusks and Annelids • Near the front end of an earthworm, the ring vessels that contract rhythmically are known as heart or aortic arches • Like many marine annelids, earthworms have sensory cells located in the skin

8. Chapter 27 ReviewMollusks and Annelids • How does an earthworm become shorter? By contracting its longitude muscles • The group of annelids that protect themselves by tufts of poisonous bristles that break off and penetrate the skin of the attacker include the fireworm

9. Chapter 27 ReviewMollusks and Annelids • In mollusks, ammonia is removed from the blood and released from the body through nephridia • In the South Pacific, many annelids that swarm at the surface to release eggs at the same time are paloloworms

10. Chapter 27 ReviewMollusks and Annelids • Describe the process of reproduction in earthworms. • They link and exchange sperm and some other stuff happens • Which term is least closely related to the others: tubifex worms; earthworm; oligochaete; polychaete • What is found in the castings of earthworms? waste

11. Chapter 27 ReviewMollusks and Annelids • Most leeches are organisms that exist as external parasites • By grinding and partially digesting incredible amounts of soil, earthworms speed the return to plants of nitrogen • Ocean plankton consists of many very small polycheates

12. Chapter 27 ReviewMollusks and Annelids • Once the skin of a host has been penetrated, a leech sucks blood from the area by using it’s pharynx • The cephalopod whose internal shell is either thin and coiled, or flat and plate-like is the cuttlefish

13. Chapter 27 ReviewMollusks and Annelids • Some nudibranchs protect themselves by bright colors • In mollusks, cellular metabolism produces nitrogen-containing wastes in the form of ammonia • An organism that has both male and female reproductive organs is called a hermaphrodite

14. Chapter 27 ReviewMollusks and Annelids • Some hermaphroditic mollusks, such as certain snails, switch from one sex to another. • Current investigations of mollusks are based on the fact that they never develop cancer

15. Chapter 27 ReviewMollusks and Annelids • Brightly-colored gills protrude from the worm’s tube in feather duster worms. • Most tube-dwelling annelids have light sensitive cells that allow the animal to detect shadows of predators passing ovehead.

16. Chapter 27 ReviewMollusks and Annelids • One reason soil deteriorates when poisons are used to kill insects is that useful organisms are also killed. • During feeding, a leech may swallow up to ten times it’s weight in blood.

17. Chapter 27 ReviewMollusks and Annelids • A leech usually attaches itself to it’s host by the anterior sucker. • The teeth of the radula have evolved into long, hollow darts attached to poison glands in snails known as cone shells