2nd half of lophotrochozoa (mollusca)

Question 1

mollusca phyllum

Answer 1

muscular foot - movement
visceral mass - most internal organs
mantle - covers the visceral mass and shell (if present)
- well develop organs within specific systems

Question 2

polyplacophora class

Answer 2

aka the chitons
found in wave-swept rocky shores

oval and flat
head is reduced
sensory organs arent concentrated in one area

Question 3

gastropoda class

Answer 3

largest and most diverse
- have torsion (twisting organs within the shell)
- broad, flat creeping foot
- rely on gas exchange

ex. snails and slugs

Question 4

bivalva class

Answer 4

• largest and most ecologically significant
• filter feeders
• compressed foot – super muscular

ex. clams and oysters

Question 5

class cephalopoda

Answer 5

• enlarged brain and head
• well developed
• tentacles for feet
• sharp beak
• well dev eyes
• closed circulatory system = fast

ex. octopus, squids, etc

Question 6

suckers

Answer 6

is in the arms and sticks to things

squid external anatomy

Question 7

siphon

Answer 7

in the neck of the squid.
moves the squid, expels waste products, pushes ink out of the body

squid internal anatomy

Question 8

funnel retractor muscle

Answer 8

allows for movement of the squid
it’s above the neck area

squid internal anatomy

Question 9

posterior vena cava

Answer 9

deoxygenates blood and pumps it

squid internal anatomy

Question 10

cecum

Answer 10

performs some digestion

squid internal anatomy

Question 11

nidamental gland

Answer 11

produces eggs and protects them

FEMALE squid internal anatomy

Question 12

chromatophores

Answer 12

cells that allow the squid to change colors – dots in their skin

squid external anatomy