Study Cards For Lab #5 Quiz

Question 1

Summary: Basic ancestral body plan of phylum Mollusca

Answer 1

Dorsal = mantle/shell
Ventral = foot
Anterior = head/ mouth
Posterior = mantle cavity/ gill

Question 2

Summary: Body plan of class Gastropoda (snails)

Answer 2

shell dextral versus sinistral

trochophore / veliger larvae

Question 3

Summary: Body plan of class Bivalvia (clams, mussels, oysters)

Answer 3

shell anatomy: (dorsal, ventral, hinge, umbone)
internal anatomy: (muscles, gills, foot, mantle, siphons, mouth, gonad)
glochidia larvae (freshwater)
locomotion (foot/ muscles)
reproduction

Question 4

Summary: Body plan of class Cephalopoda (squid, cuttlefish, octopuses, nautiluses)

Answer 4

squid external anatomy: (foot, arms (8), vs tentacles (2), eyes, funnel)
squid internal anatomy: (gills, branchial heart, retractor muscle, ink sea, stomach, cecum, pen)
squid female: (ovary, nidamental gland, accessory nidamental gland, oviduct)
squid male: (testis)
locomotion: (jet propulsion/ muscles)

Question 5

Mollusca - overview

Answer 5

more than 110 000 living species (slugs, toothshells, mussels, chitons, sea butterflies, squids, octopuses, and nautiluses) - most are marine

Question 6

Molluscs - distinctive features

Answer 6

head/foot - ventral muscular foot for locomotion
visceral mass - contains most of the organ systems
mantle - envelopes the visceral mass and secretes the shell
shell - outer periostracum of conchiolin, middle prismatic layer of crystalline calcium carbonate, inner nacreous layer
radula - peculiar to the molluscs (absent in bivalves)

Question 7

Molluscs - distinctive features part 2

Answer 7

molluscs have unsegmented bodies
schizocoelous coelomates
coelom represented by pericardial cavity and the cavity surrounding the gonads and kidney (coelomoduct
digestive system includes digestive glands, liver, radula in buccal mass
open circulatory system - heart, vessels, blood sinuses (form a hemocoel)
respiration by ctenidia (gills) or lungs
excretion by coelomoducts
nervous system - six pairs ganglia
many have trochophore larvae

Question 8

Class Gastropoda: snails, slugs, sea hares, limpets

Answer 8

largest and most varied group of molluscs
marine, freshwater, terrestrial
have undergone torsion - alimentary tract is looped with the anus positioned at the side near the head
spirally coiled shell with coiled visceral
hemaphroditic with an ova-testis
trochophore and occasionally a veliger larval stage