Unit 2: Lesson 11- Worms

Question 1

Clade Bilateria

Answer 1

Bilateral symmetry, triploblastic

Question 2

Clade Lophotrochozoa (Clade Bilateria)

Answer 2

Has lophophore feeding structure (filtering crown of cilia), and trochophore stage (ciliated larva)

Question 3

Phylum Platyhelminthes

Answer 3

Flatworms, acoelomate, closed gut (circulatory and digestive), free-living, parasite, CNS, cephalization

Question 4

Class Turbellaria (Phylum Platyhelminthes)

Answer 4

Free-living, cephalization, can reproduce asexually by regeneration, do sexual reproduction (hermaphrodites)

Question 5

Class Turbellaria (Phylum Platyhelminthes) Life Cycle

Answer 5

Adult worms lay eggs in stool that get onto vegetation, which is eaten by livestock (pigs), the intermediate host. They form cysts inside the muscle tissue, which is eaten by the definitive host, humans.

Question 6

Class Trematoda (Phylum Platyhelminthes)

Answer 6

Fluke worms, internal parasites, multiple hosts (intermediate and definitive), produce cyst

Question 7

Liver Fluke Class Trematoda (Phylum Platyhelminthes) Life Cycle

Answer 7

An adult fluke in a human lays eggs in stool that are excreted and reach the first intermediate host, a snail. The larva exit the snail in water and go to the second intermediate host, a fish. They form cysts in the muscle, and the definitive host, a human, eats the cyst-infected tissue.

Question 8

Class Cestoda (Phylum Platyhelminthes)

Answer 8

Tapeworms, solex (head) anchors to intestines, no gut because they live in a gut, proglottids are reproductive units.

Question 9

Blood Fluke Class Trematoda (Phylum Platyhelminthes) Life Cycle

Answer 9

Develops inside a snail until it becomes a swimming motile larva that burrows in the skin of a human host.

Question 10

Class Cestoda (Phylum Platyhelminthes) Life Cycle

Answer 10

An adult worm in the intestines of a human lays eggs in stool, that end up on vegetation that gets eaten by livestock. Eggs hatch into larvae that form cysts in the animal’s muscle, when eaten by humans, the cycle repeats.

Question 11

Phylum Rotifera

Answer 11

Small filter feeders, open gut, lophophore, pseudocoelomate, parthenogenesis (unfertilized eggs become female clones)

Question 12

Ecdysozoa

Answer 12

Molt out of chitin exoskeleton

Question 13

Phylum Nematoda (Ecdysozoa)

Answer 13

Pseudocoelomate, roundworms, open gut, use coelom for circulation, free-living, parasites

Question 14

Hookworms

Answer 14

Live in intestines, lay eggs in stool, eggs hatch in soil, enter through skin, worms drink blood.