Internal and external structures of animals

Question 1

A crab sheds its shell as it grows. Why?

• A. The hard external shell cannot stretch, so it must be replaced by a bigger one.
• B. It is too hot inside.
• C. Its shell is made of skin.
• D. To change colour.

Question 2

What does this internal structure do: lungs?

• A. breaks down food
• B. supports and protects the body
• C. take in oxygen from the air
• D. pumps blood around the body

Question 3

Is this an internal or an external structure: the skeleton of a dog?

• A. external (outside the body)
• B. internal (inside the body)

Question 4

A shark's skeleton is made of cartilage, not bone. Is it internal or external?

• A. internal
• B. it is made of scales
• C. sharks have no skeleton
• D. external

Question 5

What does this internal structure do: skeleton?

• A. pumps blood around the body
• B. take in oxygen from the air
• C. breaks down food
• D. supports and protects the body

Question 6

Is this an internal or an external structure: the stomach?

• A. external (outside the body)
• B. internal (inside the body)

Question 7

A crab sheds its shell as it grows. Why?

• A. It is too hot inside.
• B. To change colour.
• C. The hard external shell cannot stretch, so it must be replaced by a bigger one.
• D. Its shell is made of skin.

Question 8

What does this internal structure do: gills?

• A. controls the body and processes information
• B. pumps blood around the body
• C. supports and protects the body
• D. take in oxygen from water

Question 9

Is this an internal or an external structure: the stomach?

• A. external (outside the body)
• B. internal (inside the body)

Question 10

Insects have no bones. What holds their bodies up?

• A. their wings only
• B. nothing; they are floppy
• C. air inside them
• D. a hard outer covering (exoskeleton)

Question 11

What does this internal structure do: lungs?

• A. supports and protects the body
• B. take in oxygen from the air
• C. pumps blood around the body
• D. controls the body and processes information

Question 12

Is this an internal or an external structure: the skeleton of a dog?

• A. external (outside the body)
• B. internal (inside the body)

Question 13

Why is a skull (an internal structure) important?

• A. It digests food.
• B. It helps you breathe.
• C. It pumps blood.
• D. It protects the brain.

Question 14

What does this internal structure do: skeleton?

• A. pumps blood around the body
• B. take in oxygen from water
• C. supports and protects the body
• D. breaks down food

Question 15

Is this an internal or an external structure: the heart?

• A. external (outside the body)
• B. internal (inside the body)

Question 16

Why is a skull (an internal structure) important?

• A. It digests food.
• B. It helps you breathe.
• C. It protects the brain.
• D. It pumps blood.