Chapter 35

Question 1

Name some characteristics of mollusks.

Answer 1

They exhibit bilateral symmetry. They undergo a trochophore state. They use radula to acquire food.

Question 2

Mollusk bodies are divide into what two main regions?

Answer 2

visceral mass and head-foot

Question 3

Which region contains the mouth and sensory structures in a mollusk?`

Answer 3

head

Question 4

Which region contains the heart, digestive, reproductive, and excretory organs of a mollusk?

Answer 4

mantle

Question 5

Which mollusk structure produces the hard valves or shells?

Answer 5

mantle

Question 6

paired clusters of nerve cells controlling the locomotion, feeding, and sensory processing are located where?

Answer 6

in the head-foot and visceral mass

Question 7

A radula can be used to

Answer 7

feed

Question 8

The process that occurs in gastropods to produce a head that can be retracted is called

Answer 8

torsion

Question 9

the largest and most diverse class of mollusks

Answer 9

gastropods

Question 10

Give some examples of gastropods.

Answer 10

snails, conchs, and abalones

Question 11

The structure of a land snail that acts as a modified lung is the ___.

Answer 11

mantle activity

Question 12

The marine gastropod that has no shell is the ___.

Answer 12

nudibranch

Question 13

Most bivalves are ___.

Answer 13

sessile

Question 14

The mantel cavity of a clam is sealed except for two fleshy tubes called ___.

Answer 14

siphons

Question 15

Clams reproduce ___.

Answer 15

sexually only

Question 16

Most cephalopods are ___.

Answer 16

free swimming

Question 17

Name three facts about cephalopods and their nervous system.

Answer 17

They have the largest brain of any invertebrate. They are capable of learning. Their tentacles have numerous sensory neurons.

Question 18

Specialized pigment cells that allow a cephalopod to blend with its environment are called ___.

Answer 18

chromatophores

Question 19

A squid usually has ___ tentacle(s) used for preying on and capturing food.

Answer 19

2

Question 20

Architeuthis is the largest invertebrate. What is it?

Answer 20

giant squid

Question 21

What are some characterists of the chambered nautilus?

Answer 21

It is the only cephalopod with an external shell. It has fluid-filled chambers that help with buoyancy as it discharges water. It uses only the outermost chamber of its shell for occupancy.

Question 22

The segmented coelom of the earthworm allows for ___.

Answer 22

muscle contraction producing locomotion independent from organ function

Question 23

the common characteristic that suggests mollusks and annelids are related is ___.

Answer 23

trochophore stage of development

Question 24

The most commonly known oligochaete is the ___.

Answer 24

earthworm

Question 25

contraction of which muscle in the earthworm causes the initial increase in pressure of the coelomic fluid initiating locomotion?

Answer 25

circular

Question 26

Name two circulatory structures in the earthworm that are responsible for pumping blood.

Answer 26

dorsal blood vessel; aortic arches

Question 27

An annelid is equipped with excretory tubules to eliminate excess water. These tubules are called what?

Answer 27

nephridia

Question 28

The clitellum is responsible for \_\_\_.

Answer 28

secreting mucous that aids in the reproductive process of the annelid

Question 29

The largest class of annelids is \_\_\_.

Answer 29

polychaeta

Question 30

The class of Hirudinea includes \_\_\_.

Answer 30

leeches

Question 31

Name some characteristcs of leeches.

Answer 31

They secrete an anesthetic so the host does not feel the leech. They can ingest ten times their own body wieght in blood. They secrete an anticoagulent to keep the blood from clotting.

Question 32

The majority of polychaetes \_\_\_.

Answer 32

are covered with numerous setae and parapodia