IMO Practice Test — The Human Body: Working Systems
6 Questions • 12 min • Olympiad level
12:00
Question 1 of 6
hard
A sheet of muscle below the lungs that helps us breathe in and out is the…
Rib only
Skull
Diaphragm
Heart
Explanation: The diaphragm moves to pull air in and push it out.
Question 2 of 6
hard
In the lungs, oxygen passes into the blood and carbon dioxide passes out. This swap is called…
Evaporation
Digestion
Reflection
Exchange of gases
Explanation: The lungs exchange oxygen for carbon dioxide.
Question 3 of 6
medium
Why is it important to chew food well?
It cleans teeth only
It tastes worse
It fills the stomach with air
Smaller pieces are easier to digest
Explanation: Well-chewed food digests more easily.
Question 4 of 6
hard
Several organs working together for digestion form the digestive…
Bone
Cell
Tissue
System
Explanation: Organs that digest food form the digestive system.
Question 5 of 6
hard
The brain sends and receives messages through thin threads in the body called…
Bones
Nerves
Veins only
Hairs
Explanation: Nerves carry messages to and from the brain.
Question 6 of 6
hard
Tiny living parts of blood that fight germs are the white blood…
Hairs
Bones
Nerves
Cells
Explanation: White blood cells fight germs in the body.