EXERCISE 37: Platyhelminthes & Nematoda

EXERCISE 37: Platyhelminthes & Nematoda

PHYLUM; PLATYHELMINTHES (flatworms)

Define: 1. mesoderm-

2. acoelomate-

3. organs-

4. bilateral symmetry-

5. triploblastic-

CLASS; Turbellaria (free-living flatworms)

PROCEDURE 37.1

1. Follow steps 1-9 p. 403

2. Sketch a planaria (Dugesia) below (1-2” size). Label any visible structures.

3. Sketch a planaria cross-section from step 9 above. Label parts visible.

4. What does the planaria use its eyespots for?

5. Does a planaria move toward or away from light? Why?

6. Where is its feeding tube (pharynx) located?

CLASS: Trematoda (parasitic flukes)

Define: 1. ectoparasite-

2. Endoparasite-

3. ventral suckers-

4. monoecious-

GENUS: Opistorchis or Clonorchis (Chinese liver fluke)

1. Examine a prepared slide of this fluke. Sketch it below and label visible

structures.

2. How does the Chinese liver fluke infect humans?

GENUS: Fasciola (sheep live fluke)

1. Examine a prepared slide of this fluke and sketch below (2 “ size).

2. On what does it feed?

GENUS: Schistosoma (blood fluke)

1. What are the symptoms of people infected with Schistosomiasis from this fluke?

2. Examine a prepared slide of this blood fluke and sketch below.

3. Define: a. intermediate host-

b. definitive host-

c. dioecious-

CLASS; Cestoda (parasitic tapeworms)

1. Define: a. scolex-

b. proglottid-

c. mature proglottid-

d. gravid proglottid-

2. Examine a prepared slide of Taenia solium (pork tapeworm).

Sketch it below and label each of above listed parts.

a. How does the size of the proglottids vary from the scolex (anterior end) to the

posterior end?

b. How long can this tapeworm get to be?

c. How are humans infected by this parasite?

d. How do tapeworms obtain their food since they have no mouth or digestive

system?

PHYLUM: Nematoda (roundworms)

1. Where do non-parasitic (free-living) nematodes live?

2. What is Filaria? How is it transmitted to humans?

3. How is the digestive tract of nematodes different from that of flatworms?

4. What is loa loa?

PROCEDURE: 37.2

1. Follow steps 1-3 using a living culture of Rhabditis.

2. How would you describe its movement?

3. How does its movement relate to the muscle structure of roundworms?

PROCEDURE: 37.3

Follow steps 1-8 p. 409-410.

NOTE: When dissecting, pin all structures shown on p. 409 fig. 37.13. Instructor

will check these when you are finished. WEAR GOGGLES!

PROCEDURE: 37.4

Examine and sketch (2 “ size) prepared slides of each roundworm listed below.

1. Trichinella (causes Trichinosis)

2. Necator (hookworm)

3. Enterobius (pinworm)

4. How are humans infected by each of these worms?

Trichinella-

Hookworms-

Pinworms-