Chapter 2 Animals-Section 1

Question 1

What are four body structure characteristics of all mollusks?

Answer 1

1) invertebrates with soft unsegmented body
2) often covered by a shell
3) has a mantle
4) has a foot

Question 2

What is a mantle and what does it do?

Answer 2

A mantle is a thin layer of tissue that covers a mollusk’s internal organs.

Question 3

In many mollusks what does the mantle produce?

Answer 3

A hard shell

Question 4

What are some different functions of the mollusk’s foot?

Answer 4

The foots different functions are crawling, digging, or catching prey.

Question 5

What type of symmetry do mollusks have?

Answer 5

Bilateral symmetry

Question 6

True or false

Like segmented worms, the body parts of mollusks are usually repeated.

Answer 6

False

The body parts of mollusks are not usually repeated

Question 7

Most groups of mollusks have what type of circulatory system?

Answer 7

Open circulatory system. This means the blood is not always inside blood vessels.

Question 8

Explain how the open circulatory system works

Answer 8

The heart pumps blood into a short vessel that opens into the body spaces containing the internal organs. The blood sloshes over the organs and returns eventually to the heart.

Question 9

Most mollusks that live in water have what?

Answer 9

Gills which are organs that remove oxygen from the water

Question 10

What are tiny hairlike structures on the gills called

Answer 10

Cilia

Question 11

What is the function of the cilia?

Answer 11

The cilia move back-and-forth making water flow over the gills.

Question 12

What is the function of the gills?

Answer 12

The gills remove the oxygen from the water and oxygen moves into the blood. At the same time carbon dioxide, a waste gas, moves out of the blood and into the water.

Question 13

What is a radula and what does it do?

Answer 13

A radula is a flexible ribbon of tiny teeth used to obtain food

Question 14

What are the two shells in bivalves held together by?

Answer 14

Hinges and strong muscles

Question 15

How do you bivalves capture food?

Answer 15

Bivalves capture food as water flows over their gills. Food particles stick to the mucus that covers the girls. The cilia on the gills then move the food particles into the bivalves mouth.

Question 16

What happens if an object such as a grain of sand gets stuck between the bivalves mantle and shell?

Answer 16

The bivalve’s mantle produces a smooth, pearly coat to cover the irritating object. Sometimes a pearl forms eventually around the object.

Question 17

Give example of a cephalopod with an external shell, one with a small shell within the body, and one with no shell.

Answer 17

Nautiluses have an external shell, squids have a small shell within the body, and octopuses have no shell

Question 18

A cephalopod tentacles contain what? And what do these do?

Answer 18

Cephalopods tentacles contain sensitive suckers. The suckers receive sensations of taste as well as touch.

Question 19

How does jet propulsion work?

Answer 19

Current water is squeezed out of the mantle cavity and through a tube. Then like rockets they shoot off in the opposite direction.

Question 20

Describe a cephalopods foot?

Answer 20

A Cephalopods foot is adapted to form tentacles around its mouth.

Question 21

What are the largest group of mollusks?

Answer 21

Gastropods

Question 22

What are the physical characteristics used to classify mollusks into groups?

Answer 22

The presence of a shell, the type of shell, the type of foot, and the type of nervous system

Question 23

What are the three major groups of mollusks?

Answer 23

Gastropods, bivalves, and cephalopods

Question 24

What is a herbivore? Carnivore? Omnivore?

Answer 24

Herbivore is an animal who eats plants. A carnivore is an animal who eats other animals. An omnivore is an animal that eats both plants and other animals.