Lab 9 - Mollusca

Question 1

Are mollusca lophotrochozoans or ecdysoans?

Answer 1

Lophotrochozoans

Question 2

What are the four classes of mollusca?

Answer 2

polyplacophora, gastropoda, cephalopoda, bivalvia

Question 3

What organisms are found in the class polyplacophora?

Answer 3

Chitons

Question 4

What organisms are found in the class gastropoda?

Answer 4

snails and slugs

Question 5

What is torsion and what class can do it?

Answer 5

the body folds 90 to 180 degrees - gastropoda do this

Question 6

What organisms are in the class bivalvia?

Answer 6

clams and relatives :)

Question 7

What organisms are in the class cephalopoda?

Answer 7

squids, octopuses, cuttlefish, and nautilus

Question 8

What kind of symmetry do mollusca have?

Answer 8

bilateral

Question 9

Are mollusca deuterostomes or protostomes?

Answer 9

protostomes

Question 10

Do mollusca shed a cuticle to grow?

Answer 10

hell no

Question 11

What level of organization are mollusca?

Answer 11

organ-system

Question 12

What kind of body cavity do mollusca have?

Answer 12

coleom

Question 13

How many germ layers do mollusca have?

Answer 13

3 - triploblastic

Question 14

What are the distinctive features of mollusca?

Answer 14

mantle, mantle cavity, visceral mass, and foot

Question 15

What is a mantle?

Answer 15

epidermal sheet of skin that secretes the shell

Question 16

What is a mantle cavity?

Answer 16

fold in the mantle that houses gills, opening anus

Question 17

What is the visceral mass?

Answer 17

enclosed by the mantle, where most vital organs are located

Question 18

What is a foot? (not the human foot, the mollusca foot)

Answer 18

muscular tissue used for movement; can be drawn into the shell

Question 19

What kind of digest system do mollusca have?

Answer 19

complete (mouth and anus)

Question 20

What are radula in mollusca?

Answer 20

tongue-like organ that is for feeding (scrapes)

Question 21

Where are radula not found?

Answer 21

bivalvia

Question 22

What kind of circulation do mollusca have?

Answer 22

open in most
closed in cephalopods

Question 23

How do aquatic mollusca respire?

Answer 23

gills

Question 24

How do terrestrial mollusca respire?

Answer 24

vascularized mantle wall

Question 25

How do mollusca excrete?

Answer 25

Pair of metanephridia - connected to coelom

Question 26

What kind of sensory systems do mollusca have?

Answer 26

varying degrees of cephalization, several pairs of ganglia with connecting nerve chords, complex brain/eyes

Question 27

What kind of support system do mollusca have?

Answer 27

external shell (bivalves, most gastropods); internal shell (cuttlefishes); internal shells known as pens (squids); no shells (octopuses

Question 28

Mollusca - locomotion (how do they do it?)

Answer 28

most move with their muscular foot; cephalopods have a mantle modified for water jet propulsion - siphon

Question 29

How do mollusca reproduce?

Answer 29

external fertilization for some, most are internal; monoecious or dioecious (majority)

Question 30

What is the difference between open and closed circulatory systems?

Answer 30

open: fluid leaves vessels (arteries)
closed: fluid stays in vessels (arteries)

Question 31

What is a benefit of having a closed circulation system?

Answer 31

mollusca with a closed system can move faster and grow larger