Lecture 12: Nematodes & Annelids Flashcards
1
Q
Coelomate
A
- mesoderm lines entire cavity as “peritoneum”
2
Q
Pseudocoelomate
A
- mesoderm lines outside of pseudocoel
- “false coelom”
3
Q
Acoelomate
A
- no body cavity (only gut)
- solid except for digestive space
4
Q
Two ways to make a coelom
A
- Schizocoely: splitting with mesoder; protostome way
2. Enterocoely: mesoderm forms pockets from gut; deuterostome way
5
Q
Protostomes divided into two groups
A
Lophotrochozoans
Ecdysozoans
6
Q
Lophotrochozoans
A
either have
- lophophore: ciliated feeding; gas exchange structure
- trochophore: ciliated free larval form used for locomotion and feeding
7
Q
Ecdysozoans
A
- have external covering secreted by epidermis that must be shed in order to grow
8
Q
Nematoda
A
- protostome
- ecdysozoan
- pseudocoelomates
- move by thrashing
- hydrostatic skeleton
- tapered posterior end
- blunt anterior end
- important part of food web of soil
9
Q
C. Elegans
A
- type of nematoda
- research on them revolving around aging
- they identifies 4 genes that were mutated that allowed them to live longer, have more energy, feed and swim at a lower pace
10
Q
Hookworm
A
- type of nematode
- goes through barefoot
- feeds on red blood cells
11
Q
Annelida
A
- lophotrochozoans
- coelomates
- have segments
- move by contracting circular and longitudinal muscles
- hydrostatic skeleton
12
Q
Segmentation advantage?
A
- multiple copies of organs/structures
- efficient nervous system (ganglion at each segment, so faster responses)
- increases body size by unit repetition
13
Q
Advantages of circulatory system
A
- deeper tissue and surface
- gut and muscles allow for more nutrient delivery
- permits development of a TICK body
14
Q
Polyplaeta
A
- annelid
- means “many hairs”
- marine
- have parapodia (used for locomotion and respiration)
- trochophore larvae
- have tubes they can retract into during low tide
15
Q
Oligochaeta
A
- annelid
- terrestrial
- hermaphroditic
- secretes mucus cocoon for embryo development
- no specific larval stage
