ch. 33 triploblastic acoelomates Flashcards
1
Q
phylum of triploblastic acoelomates
A
- phylum platyhelminthes
- phylum nemertea
2
Q
classes of phylum platyhelminthes
A
- class turbellaria
- class monogenea
- class trematoda
- class cestoda
3
Q
phylum platyhelminthes characteristics
A
- acoelomates
- flatworms
- lack specialized respiratory/circulatory system
- respire by diffusion
- bilaterally symmetrical w/ head
4
Q
platy
A
flat
5
Q
helminth
A
parasitic worm
6
Q
digestive system of phylum platyhelminthes
A
incomplete - one opening for mouth/anus
7
Q
excretory system for phylum platyhelminthes
A
distinct with protonephridia and flame cells
8
Q
eyes in phylum platyhelminthes
A
light sensitive eyespots (ocelli)
9
Q
nervous system in phylum platyhelminthes
A
- cerebral ganglia receive input
- more centralized nervous system
10
Q
reproduction in phylum platyhelminthes
A
sexual or asexual
- most hermaphroditic but don’t self-fertilize
11
Q
class turbellaria
A
- planarians
- live in fresh water and prey on smaller animals
- ocelli and centralized nerve nets
- hermaphrodites - sexual reproduction or fission
12
Q
class trematoda
A
- parasitize wide range of hosts
- those that parasitize humans spend part of lives in snails
- produce surface proteins that mimic host
- release molecules that manipulate host’s immune system
13
Q
class cestoda
A
- tapeworms or parasitic worms
- head = scolex w/ several suckers
- suckers attach to intestine walls of host and absorb food as it is digested
- doesn’t kill host but causes weight loss
14
Q
length of human tapeworms
A
18 meters
15
Q
what is the body of a tapeworm divided into?
A
sections called proglottids
