NAME
COMPARATIVE ANATOMY
1. Observe the fluke or tapeworm which a member of Phylum Platyhelminthes, “flat worms”. Why is “flat worms” an
appropriate for name for this group?
2. Observe the Ascaris which is a member of Phylum Nematoda, “round worms”. Why is “round worms” an
appropriate for name for this group?
3. Observe the earthworm or leech which is a member of Phylum Annelida, “segmented worms”. Why is “segmented
worms” an appropriate for name for this group?
4. What type of symmetry do member of all three phyla have?
5. Members of Platyhelminthes, Nematoda, and Annelida are cephalized. What does this term mean?
6. What advancement in digestion is seen in the group Nematoda?
7. What level of organization seen in each phylum (cells, tissues, organs, organ systems)?
A) Platyhelminthes
B) Nematoda
C) Annelida
8. Compare the symmetry, level of organization, and cephalization of the worms to the Poriferans (Sponges) and
Cnidarians.
MOVEMENT & REPRODUCTION
Observe the locomotion of the Planaria which is in Phylum Platyhelminthes, “flat worms” under the dissecting
microscope. Next, view the videos showing the locomotion of the Ascaris which is in Phylum Nematoda, “round worms”,
and the earthworm which is in Phylum Annelida, “roundworms”.
1. Why is the movement in each of these worms different?
2. Rub your finger along the earthworm. What is the name of the tiny hairs on the surface of the earthworm? What is
their function?
Observe the planarian which is in Phylum Platyhelminthes, “flat worms” under the dissecting microscope.
3. Members of Platyhelminthes are able to regenerate. What does this mean? Is this asexual or sexual reproduction?
4. Members of Platyhelminthes are hermaphroditic. What does this term mean?
5. Members of Annelida use a structure called a clitellum for reproduction. Read the reproduction section on page 696
of the textbook. In your own words, describe what the clitellum is and how it works.
POSITIVE & NEGATIVE CONTRIBUTIONS
1. Describe the following parasitic examples of the “flat worms” (Phylum Platyhelminthes) on page 687-688.
A) Flukes
B) Tapeworms
2. Describe the following parasitic examples of “round worms” (Phylum Nematoda) on pages 690-692.
A) Hookworms
B) Filarial Worms
C) Ascarid
3. Describe the parasitic leeches of “segmented worms” (Phylum Annelida) on page 698.
4. Read “Ecology of Annelids” on page 699 of the textbook. List and describe the positive contributions of annelids.