Mollusca Test

Question 1

Radula

Answer 1

Tongue with rough scraping teeth used for feeding

Question 2

What are two methods mollusk use to feed?

Answer 2

Filter feeders (clams, oysters) and predation (squid, octopus)

Question 3

All classes EXCEPT ___________ have a radula

Answer 3

Bivalves and aplacophora

Question 4

Visceral mass

Answer 4

Digestive system, excretory system, reproductive organs

Question 5

What does the mantle do?

Answer 5

Secretes shell

Question 6

What are the 3 layers of shell?

Answer 6

Periosteum
Prismatic
Nacreous

Question 7

What is the outside layer of a shell?

Answer 7

Periosteum

Question 8

What is the middle layer of a shell that gives it strength?

Answer 8

Prismatic

Question 9

What is the inner “mother of pearl” layer of a shell?

Answer 9

Nacreous

Question 10

Most mollusks have an _____ circulatory system

Answer 10

Open

Question 11

Because there’s no distinction between blood and interstitial fluid this is called

Answer 11

Hemolymph

Question 12

What are gills also called

Answer 12

Ctenidia

Question 13

What are the kidneys called?

Answer 13

Nephridia

Question 14

What are the seven classes of mollusca?

Answer 14

• gastropada
• bivalvia
• Cephalopoda
• Scaphopoda
• aplacophora
• monoplacophora
• polyplacophora

Question 15

How do most mollusks reproduce?

Answer 15

External fertilization

Question 16

What are characteristics of gastropada?

Answer 16

Shell conical, coiled, or absent

Question 17

What is the largest class of mollusks?

Answer 17

Gastropada

Question 18

What is torsion?

Answer 18

Developmental process in which the body twists into permanent loop that rearranges organs and brings them together allowing body to draw into spiral shell

Question 19

What is the operculum?

Answer 19

Protects the mouth of the gastropod and acts as a trap door

Question 20

What is the gastropod that has no shell?

Answer 20

Nudibranch (sea slug)

Question 21

What are characteristics of bivalvia?

Answer 21

• contain mollusks with two shells
• laterally compressed for filter feeding
• shell closed by adductor muscles
• not all bivalves burrow, mussels secrete byssal threads to attach to rocks, oysters cement left shell to hard surface
• scallops live unattached, can swim short distances

Question 22

How do cuttlefish differ from squid and octopuses?

Answer 22

By having an internal shell for buoyancy (cuttlebone)

Question 23

How do squid differ from cuttlefish and octopuses?

Answer 23

Streamlined body for open water

Question 24

How are octopuses different from cuttlefish and squid?

Answer 24

Have no shell and live in rocky reefs

Question 25

Nautilus

Answer 25

Have external shell and can live in depths of 2000 feet

-has most tentacles or arms

Question 26

What are characteristics of the class Cephalopoda?

Answer 26

• use siphon to rapidly shoot water to escape/catch food
  
  • siphon can rotate in any direction to change speed/ direction
• all but nautilus have ink sac opening
• have pigment called chromatophores

Question 27

Monoplacophora

Answer 27

-“one plate”

Question 28

Polyplacophora

Answer 28

Have oval shell consisting of 8 plates bounded by girdle

-ex: chiton

Question 29

Scaphopoda

Answer 29

(Tusk shells) marine sand burrowers with tusk or toothed shells

Question 30

Aplacophora

Answer 30

Lack of shell

-ex: worm like species

Question 31

All mollusks have

Answer 31

Mantles