Mollusca

Question 1

What are the classes of mollusca?

Answer 1

Polyplacophora - chitons
Gastropoda - snails, slugs
Bivalvia- mussels, cockles, clams
Cephalopoda- octopus , squid , nautilus

Question 2

What are molluscs?

Answer 2

Soft
100,000 species
Mantle secretes shell
Ctenidia in mantle cavity
RADULA for feeding
Foot is for locomotion
Heart, digestive, excretory and reproductive organs in visceral mass

Question 3

Why is the body plan of a mollusc special?

Answer 3

Basic body plan with FOOT, MANTLE AND VISCERAL MASS

Question 4

GENERA TO REMEMBER

Answer 4

Lephidochiton, helix, patella, arion, mytillus, pecten, octopus, sepia.

Question 5

What are polyplacophora?

Answer 5

Many shells
8 overlapping segmented shells
Herbivores, scrape algae off rocks with radula
Attached to rock by foot

Question 6

What are gastropoda?

Answer 6

Stomach foot
Torsion of visceral mass by 180 degrees
Some can swim or gallop
Terrestrial members - VASCULARISED LUNG

Question 7

What are bivalvia?

Answer 7

Two shells
Hinged 
No radula
Use ctenidia to extract fod from water
Bring water through siphon expelling through another

Question 8

Cephalopoda

Answer 8

Head foot
Mantle cavity and siphons arranged for jet propulsion
Active predatorss
Eyes highly developed
Courship and learninh 
Die after breeding 
VERY ADVANCED FOR INVERTEBRATES