bio145 lab 5

1. a. What are the three classes of mollusks? (3
points)

b. Explain the
shells of each of the three classes of mollusks. (3 points)
c. Name one
example of each of the three classes of mollusks. (3 points)
2. What is the largest class of mollusks? (1 point)
3. Name one cephalopod that still has a shell. (1 point)
4. Why is the name cephalopod appropriate for this class of
animals? (1 point)
5. a. What does it mean to exhibit bilateral symmetry? (1
point)
b. Which side of a
squid is the dorsal side? (1 point)
c. Which side of a
squid is the ventral side? (1 point)
6. a. How many tentacles are found on a squid? (1
point)
b. What is the
function of the tentacles? (1 point)
c. How many arms
are there on a squid? (1 point)

d. What is the
function of the arms? (1 point)
e. How is the
arrangement of suckers on the tentacles different from the arrangement on the
arms? (1 point)
7. a. How does a squid maintain body stability? (1
point)

b. How does a
squid propel itself through the water? (1 point)
8. How does a male squid transfer sperm from its body to
that of the female? (1 point)
9. a. How do squid bring oxygen into their bodies? (1
point)

b. How do they get
rid of carbon dioxide? (1 point)
10. Identify the functions of the following structures: (10
points)

a. beak
b. eye
c. ganglia
d. hearts
e. mantle
f. pen
g. radula
h. stomach
i. suckers
j. testes

11. What is the olfactory crest? (1 point)
12. What are two ways that squid can protect themselves from
predators? (2 points)
13. The pen is the vestigial internal shell of the squid.
What does the term vestigial mean? (1 point)
14. a. What is an advantage of having a shell? (1
point)

b. What is an
advantage of not having a shell? (1 point)

–Answer below:
15. How many species of cephalopods are found in freshwater?
(1 point)
17. How many hearts does a squid have? (1 point)
19. What are chromatophores? (1 point)
20. a. Was the squid male or female? (1 point)

b. What was the distinguishing characteristic?
(1 point)