Exercises 37 and 38b

Question 1

Why is Platyhelminthes a thing? What are its classes?

Answer 1

Platyhelminthans are acoelomate, flatworms, bilaterally symmetric, have a single gastrovascular opening. Classes Turbellaria, Trematoda, and Cestoda

Question 2

Describe the classes of Platyhelminthes and list each one’s members.

Answer 2

Turbellaria: Planarians [Dugesia]
Trematoda: Flukes [Schistosoma, Opisthorchis, Fasciola]
Cestoda: Tapeworms [Taenia]

Question 3

Why is Nematoda a thing?

Answer 3

Nematodes are pseudocoelomate, bilaterally symmetric, roundworms, have a complete digestive tract, and very varied. It only has longitudinal muscles and a flexible cuticle. Uses hydrostatic pressure.

Question 4

What are the members of Nematoda?

Answer 4

Ascaris [Classic roundworm] [Male/female]
Turbatrix [Tiny jiggly worms]
Trichinella [Trichinosis cysts in striated muscle]
Ancylostoma [Ankylosaurus, jaw roundworm]
Enterobius [Pinworm]

Question 5

Why is Annelida a thing? What are its classes?

Answer 5

Annelidans are fully coelomate, segmented worms, with closed circulatory system, and setae. Polychaeta, Oligochaeta, Hirudinea.

Question 6

Describe the classes of Annelida and list each one’s members.

Answer 6

Polychaeta: Many setae [Nereis marine worm w/ parapodia]
Oligochaeta: Some setae [Lumbricus earthworm]
Hirudinea: No setae [leeches]

Question 7

What is triploblastic?

Answer 7

Having three layers, ectoderm, mesoderm, and endoderm.

Question 8

Describe class Trematoda

Answer 8

Opistorchis: Oriental fluke. Dark part: gastrovascular; light part: reproductive part
Fasciola: Sheep liver fluke.
Schistosoma: NOT hermaphroditic. Intestinal blood vein inhabitant. Snails are intermediate host. Male w/groove [large, red] + female [small, black].

Question 9

Describe class Cestoda

Answer 9

Taenia: Tapeworm. No mouth or digestive tract. Made up of segments called proglottids. Has scolex w/ hooks or suckers. Immature, Mature, Gravid proglottids.

Question 10

How do earthworms move?

Answer 10

Hydrostatic pressure. Alternating contraction of longitudinal and circular muscles.

Question 11

Parts of earthworm:

Answer 11

Seminal vesicles: sperm mature
Pharynx: suction, ingestion
Heart: blood circulation
Esophagus: transport
Crop: storage/digestion
Gizzard: maceration/crushing
Intestine: absorption

Question 12

Leeches have ____ suctions and ____ segments.

Answer 12

two, zero

Question 13

Digestion

Answer 13

Porifera: Intracellular filter feeding. No mouth
Cnidaria: Some intracellular, extracellular. One opening.
Platyhelminthes: One mouth.
Nematoda: Two openings.
Annelida: Two openings