Phylum ctenophora Flashcards
1
Q
adhesive cells
A
colloblast
2
Q
8 rows of comb like plates
A
ctenes
3
Q
clade bilateria
A
all exhibit primary bilateral symmetry
also see cephalization
4
Q
Why do we see cephalization in bilateria?
A
more active lifestyle requires a different form
all are triploblastic
5
Q
Nervous system (platyhelminth)
A
- cephalization but vary in complexity
- most simple is subepidermal nerve net plexus (seen in some Turbellarians)
- others additionally have 1-5 pairs of
longitudinal nerve cords (“ladder”) - “brain” – mass of ganglion cells
- differentiation of neurons into types
6
Q
Sense organs ? (platyhelminth)
A
- abundant tactile & chemoreceptive cells
- form organs (auricles ) in planarians
- statocysts for equilibrium
- eyespots ( ocelli ) in some members
7
Q
Nutrition & digestion
A
- mouth, intestine & pharynx (muscular & protruding in turbellarians)
- extracellular digestion via intestinal secretions
- intracellular digestion after phagocytosis by intestinal cells
- undigested food expelled via pharynx( blind gut)
8
Q
rhabdites
A
form protective mucous sheath
9
Q
eyespots
A
ocelli
10
Q
from organs in planarians
A
auricles
11
Q
Excretion & osmoregulation( platyhelminthes )
A
- canals with tubules ending in flame cells (protonephridia)
- flagella beat to create negative pressure to draw in fluid
- collecting ducts open to outside via pores
- metabolic waste removed via diffusion through body wall
12
Q
Reproduction
A
- many via asexual and sexual means
-asexual reproduction can be via regeneration
-parent constricts in middle
-each half generates missing end
-parasitic flukes reproduce asexually in
mollusc intermediate host
also sexual reproduction - cross fertilization even though monoecious (hermaphroditic)
13
Q
protonephridia
A
canals with tubules ending in flame cells.
14
Q
hermaphroditic
A
cross-fertilization even though monoecious
15
Q
clamp using hooked attachment organs called
A
opisthaptor
