Name: 

Mollusks

 
True/False
Indicate whether the sentence or statement is true or false.
 

1. 

Mollusks must eat constantly because the functioning of their nephridia causes the disposal of useful molecules as well as of waste products.
 

2. 

Unlike arthropods, mollusks are unsegmented; instead, they are divided into three regions.
 

3. 

Mollusks have four distinct body parts: a foot, a head, a visceral mass, and a tail.
 

4. 

In terrestrial snails, the mantle cavity functions as a simple lung.
 

5. 

Most bivalves have separate sexes, but some are hermaphroditic.
 

6. 

Due to the presence of a shell, all gastropods are capable of living on land for at least a portion of their lives.
 

7. 

Since cephalopods have tentacles, they have no need for a radula.
 

Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
 

8. 

All of the following are characteristics of mollusks except that they have
a.
a pseudocoelomate body plan.
c.
a complete digestive tract.
b.
bilateral symmetry.
d.
an open circulatory system.
 

9. 

The cilia of a trochophore larva
a.
allow attachment to the ocean bottom.
b.
create currents for drawing in food.
c.
cover the entire larval body.
d.
are necessary for reproduction.
 

10. 

Trochophore larvae
a.
are found in molluscan life cycles.
b.
possess a belt of cilia around their bodies.
c.
occur in annelid life cycles.
d.
All of the above
 

11. 

A characteristic structure found in many mollusks is the radula, which is involved in
a.
jet propulsion.
c.
eating.
b.
opening and closing of the shells.
d.
reproduction.
 

12. 

All of the following are classes of the phylum Mollusca except
a.
bivalves.
c.
gastropods.
b.
cephalopods.
d.
pseudopods.
 

13. 

The only mollusks that have a closed circulatory system are
a.
bivalves.
c.
chitons.
b.
cephalopods.
d.
gastropods.
 
 
      mollusks_files/i0160000.jpg
 

14. 

Refer to the illustration above. Which two organisms in the diagrams possess mantles?
a.
Organisms “A” and “C”
c.
Organisms “A” and “D”
b.
Organisms “B” and “C”
d.
Organisms “B” and “D”
 

15. 

“Jet propulsion” is the usual means of locomotion in water for
a.
arthropods.
c.
cephalopods.
b.
echinoderms.
d.
annelids.
 
 
      mollusks_files/i0190000.jpg
 

16. 

Refer to the illustration above. The organism shown in this diagram is a
a.
bivalve.
c.
chiton.
b.
cephalopod.
d.
gastropod.
 

17. 

Refer to the illustration above. This organism possesses a(n)
a.
simple lung.
c.
internal beak.
b.
closed circulatory system.
d.
open circulatory system.
 

18. 

Refer to the illustration above. Movement of this organism is dependent upon the structure labeled
a.
“1.”
c.
“3.”
b.
“2.”
d.
None of the above
 

19. 

Shells of mollusks
a.
may consist of one or more pieces.
c.
allow for the attachment of muscles.
b.
provide protection.
d.
All of the above
 

20. 

Adductor muscles are responsible for
a.
moving the valves of bivalves.
c.
pumping the hearts of mollusks.
b.
extending the feet of mollusks.
d.
fanning the gills of aquatic mollusks.
 



 
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