Phylum Platyhelminthes Flashcards
Commonly called _
flatworms
Platyhelminthes germ layer
Endoderm, mesoderm, ectoderm
Bilateral symmetry first appears in _
Platyhelmithes
What is cephalization?
Possessing a head where central nervous system (cerebral ganglion) and sensory organs are located
Can a planaria continuously eat? Why or why not?
Cannot due to the fact that pharynx acts as both throat and anus
what feature is missing in flatworms?
anus
what organism is intermediate host for Trematoda repro?
snail
what feature is critical to tapeworm repro?
proglottid
what is one common way humans contract tapeworms
eating uncooked meat
anterior
mouth
posterior
booty
dorsal
back
ventral
front
In flatworms what is evolutionarily significance
flattened dorsoventrally
How are nerve cords found in this phylum
in pairs
in freshwater flatworms how many lateral nerve cords are there connected to cerebral ganglia
one
How does osmoregulation occur in this phylum? (what type of cells are lined with _)
flame cells lined with cilia drive fluids through a series of tubules which open to outside through a series of pores
How does excretion and respiration happen in this phylum?
simple diffusion
flattened body aids in process which is easier for diffusion
what in Class turbellaria
free living flatworms
whats in class monogenea
small ectoparasites on fish
what is in class Trematoda and what kind of parasitism
flukes, endoparasites
class cestoda
tapeworms
example organism for class turbellaria
Planaria (genus Dugesia)
digestive system of turbellaria
y shaped with eversible pharynx for feeding (mouth but no anus)
turbellaria reproduction
asexual by fission
sexual via syngamy
are animals of this phylum virtually all monoecious or diecious?
monoecious
What class includes ectoparasited
monogenea
Monogenea can be found where on host?
found on external surface of fish, amphibians, and reptiles
how do monogenea attach to host?
via a haptor
monogenean repro
sexual only
1 offspring/egg
class Trematoda how many hosts in life cycle?
2 or 3
For trematoda the definitive host is almost always a
vertebrate
What is the intermediate host for trematoda
snail
Adult human liver fluke
clonorchis sinesis
Explain life cycle of clonorchis
human poops out egg contining miracidium larvae>miracidium hatch after being eaten by snail>goes through sporocyst (shizogony stage)>then feeding stage(redia)> then turns into cercaria> which then goes into cyst in fish muscle
what is human liver fluke?
caused by clonorchis (sinensis) and often called clonorchiasis
how many people worldwide are infected with schistosomiasis
250 mil
what is schistosomiasis caused by
human blood fluke (scistosoma sp)
What is special about schistosomiasis reproduction?
adults are dioecious and the female lives in an external canal of male
And eggs pass from circulatory system and go out through poop or pee, infected via contaminated water
what is swimmers itch caused by
caused by avian schistosoma
what class includes tapeworms
cestoda
tapeworms are which kind of parasite?
endoparasite
what does tapeworm consist of (head and body name)
head-scolex
body-proglottids
Proglottid anatomy whats inside
repro organs, both male and female
Life cycle of beef tapeworm
human eats beef> poops out shelled larva>grass contaminated with eggs ingested by cow> cysts in muscle (measly beef)
What other animals can have tapeworms
dogs cats humans
any kind of meat fish poultry
What animal does this cross section belong to
Common freshwater Turbellarian - Dugesia
