IMO Practice Test — Neural Control and Coordination
6 Questions • 15 min • Olympiad level
15:00
Question 1 of 6
Impulses pass across a synapse in one direction only because neurotransmitters are released from:
One side and received on the other
Both sides equally
The muscle only
The bone
Explanation: Only one neuron releases neurotransmitters and only the next one has receptors, fixing the direction.
Question 2 of 6
A reflex action is faster than a normal voluntary action mainly because the decision is made by the:
Spinal cord, not the brain
Cerebrum
Skin
Heart
Explanation: Bypassing the brain and using the short spinal pathway makes reflexes very fast and protective.
Question 3 of 6
Damage to the cerebellum would most likely affect a person's:
Balance and coordinated movement
Heartbeat
Digestion
Memory of facts only
Explanation: The cerebellum governs balance and coordination, so its damage disturbs these.
Question 4 of 6
Reading a book and then deciding to turn the page is a voluntary action controlled mainly by the:
Cerebrum
Medulla
Spinal cord alone
Cerebellum only
Explanation: Conscious, decided actions are directed by the cerebrum.
Question 5 of 6
When you enter a dim room, the pupil widens. This adjustment of light entering the eye is controlled by the:
Iris
Retina
Optic nerve
Cornea
Explanation: The iris changes the size of the pupil to control how much light enters.
Question 6 of 6
Constant exposure to very loud noise can harm hearing because it can damage the receptors in the:
Cochlea of the inner ear
Retina
Taste buds
Skin
Explanation: Loud noise damages the delicate sound receptors of the cochlea, reducing hearing.