Platyhelminthes, Syndermata, Nematoda

Question 1

Phylum Platyhelminthes

Answer 1

“flat worms”, some are “free living”= not parasitic

Question 2

Phylum Platyhelminthes Characteristics

Answer 2

bilateral, triploblastic, acoelomate, closed gut, gas exchange: passive, through skin (flat morphology; increases surface area to volume ratio)

Question 3

Cephalization

Answer 3

sensory and nervous tissue at the front

Question 4

Protonephridia

Answer 4

osmotic balance

Question 5

Lophotrochozoa Clade

Answer 5

common ancestor, shared qualities
feeding structure: lophophore (suspension feeding)
larval form: trochophore larval form

Question 6

Class Turbellaria

Answer 6

free living = not parasitic
Phylum Platyhelminthes

Question 7

Class Trematoda

Answer 7

“flukes”, loss of cephalization = parasites
Most have 3 hosts
Ex. Schistosomiasis (only 2 hosts)

Question 8

Schistosomiasis Lifecycle

Answer 8

cilated larva -> snail host -> motile larva -> human host -> mature fluke

Question 9

Definitive/Determinate Host

Answer 9

where sexual reproduction occurs (in mammal or bird)

Question 10

Intermediate Hosts

Answer 10

other hosts

Question 11

Class Cestoda

Answer 11

tapeworms, don’t have a gut (uses host’s gut to feed)
Proglottids- repeating units, both male and female
Scolex- attachment to host
Phylum Platyhelminthes

Question 12

Phylum Syndermata/Rotifera

Answer 12

“Rotifers”, bilateral, pseudocoelomate, triploblastic, parthenogenesis

Question 13

Parthenogenesis

Answer 13

population almost exclusively female
environmental stress: production of males -> sexual reproduction
Phylum Syndermata/Rotifera

Question 14

Ecdysozoa Clade

Answer 14

exoskeleton made of chitin
Includes Nematoda and Arthropoda

Question 15

Phylum Nematoda

Answer 15

“round worms”, bilateral, triploblastic, pseudocoelomate, open gut (2 openings)
Ex. pinworms, hookworms, trinchinella (trichenosis)