Ch. 10: Phylum Mollusca Flashcards
1
Q
Are molluscs triploblastic or diploblastic?
A
Triploblastic
2
Q
Body symmetry
A
Bilateral
3
Q
Body plan
A
- Mantle (+ 3 layer shell)
- Mantle cavity
- Head-foot + visceral mass
4
Q
Digestive system
A
Open and complex
- Radula used to scrape food
5
Q
Circulatory system
A
Open circulatory (except for squid)
6
Q
What class in molluscs does not have a radula?
A
Bivalves
7
Q
Excretory system
A
By metanephridia
8
Q
Are they acoelomate, pseduocoelomate, or coelomate?
A
Coelomate
9
Q
Respiration
A
By gills or lungs in the mantle cavity
10
Q
3 Classes in Mollusca
A
- Bivalvia
- Gastropoda
- Cephalopoda
11
Q
Class Bivalvia
A
- Clams, mussels, scallops
- Foot becomes a ‘blade’
- Do not have radula
- Deposit & suspension feeders
- Reproduce mostly externally
12
Q
Class Gastropoda
A
- Snails, slugs
- Cephalization: torsion of shell and body cause gills to be reduced
- Internal fertilization
13
Q
Class Cephalopoda
A
- Squid, octopus, nautilus
- Anterior foot became tentacles
- Posterior foot became funnel
- Shell divided by septa but coiled in Nautilus
- Jet propulsion
- External or internal fertilization (separate species)
