Download Zoology Chapter 27 Worms and Mollusks Study Guide

Zoology Chapter 27 Worms and Mollusks Study Guide / Mr. Lemmons
Put your answers on separate notebook paper and before submitting, staple these questions to them.
Section 27-1 / Flatworms
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To what Kingdom do flatworms belong?
To what Phylum do flatworms belong?
What are the key characteristics of flatworms? (bold in textbook)
Flatworms have bilateral symmetry. What does this mean?
Most flatworms exhibit cephalization and have a distinct head. What does cephalization
mean?
6. What are the three embryonic tissue layers?
7. Diffusion helps flatworms perform what essential bodily functions?
8. Most parasitic flatworms do not have a complex digestive system or lack one completely.
Why?
9. Some free-living flatworms reproduce asexually by fission. Describe this process.
10. Free-living marine or freshwater flatworms; turbellarians. Class ______________
11. Internal or external parasitic flatworms that usually infect the internal organs of their
host; flukes. Class ______________
12. As adults these parasitic flatworms are long and adapted to live inside the intestines of
their hosts; tapeworms. Class ______________
13. Explain how walking barefoot affects a person’s chance of becoming infected with the
blood fluke Schistosoma.
14. How can humans become infected with a tapeworm by eating meat from a cow?
27-2 Roundworms
15. To what Kingdom do roundworms belong?
16. To what Phylum do roundworms belong?
17. A single rotting apple can contain how many roundworms?
18. What are the key characteristics of roundworms? (bold in textbook)
19. Group of parasitic roundworms that are transmitted from host to host through biting
insects, especially mosquitoes:
20. Group of parasitic roundworms that cause malnutrition and are spread by eating food that
are not washed properly:
21. Group of parasitic roundworms that us sharp teethlike structures to enter unprotected feet
of a host:
22. How is trichinosis transmitted and how could its transmission to humans be most easily
interrupted?
23. Draw a person with one leg affected by elephantiasis. (Figure 27-9)
24. Ascaris lumbricoides, a parasitic roundworm, can block the host's intestine absorbing the
host's digested food. This can cause severe malnutrition. Blockage of the intestine can be
severe enough that it causes death. List the 5 steps in the sequence of an Ascaris
infection of a human being. (Figure 27-10)
27-3 Annelids
25. To what Kingdom do annelids belong?
26. To what Phylum do annelids belong?
27. What are the key characteristics of an annelid? (bold in textbook)
28. Draw & label the three germ layers of an annelid showing its true coelom. (Figure 27-12)
29. Earthworm food digestion begins with food entering the mouth and waste exiting at the
anus. In between the mouth and anus, list the digestive system organs and their
functions.
30. Annelids have a ____________________ circulatory system.
31. How does an earthworm breath (respire)?
32. Two earthworms can fertilize each other’s eggs. True or False
33. Live in soil or freshwater; has only a few setae; includes earthworms. Class __________
34. External parasites that feed on the blood and body fluids of their host; leeches. Class ___
35. Marine annelids with pairs of paddle like appendages, each of which carry setae; includes
sandworms and bloodworms. Class __________
36. Earthworms grow up to 4 meters in the tropics; What length of castings (= feces) have
been found?
37. Describe the medicinal use of leeches.
38. Describe how earthworms contribute to the health of plants.
27-4 Mollusks
39. To what Kingdom do mollusks belong?
40. To what Phylum do mollusks belong?
41. What are the key characteristics of a mollusk? (bold in textbook)
42. The mollusk phylum is diverse. But many mollusks share similar developmental stages.
Many aquatic mollusks have a free-swimming larval stage called a trochophore
(TRAHK-oh-fawr). Draw and label this stage. (Figure 27-20)
43. The body plan of most mollusks include a: _________________, __________________,
__________________, and a ____________________.
44. Mollusks that are shell-less or single-shelled; move by using a muscular foot located on
the ventral side; snails, slugs, sea hares, limpets, nudibranchs. Class _____________
45. How can a shell-less gastropod protect itself?
46. Mollusks that have two shells held together by one or two powerful muscles; clams,
oysters, mussels, and scallops. Class ____________________
47. How can a scallop move?
48. Soft-bodied mollusks in which the head is attached to a single foot. The foot is divided
into tentacles with sucking disks or arms; octopi, squid, cuttlefishes, and nautiluses.
Class ____________
49. Concerning shells, how does an octopus compare with a squid?
50. How can mollusks be used to monitor environmental conditions?