Control and coordination-2

The diagram shows a simple reflex arc. What is the correct order of events after the knee is tapped?

• A 1 → 2 → 3 → 4

• B 1 → 4 → 2 → 3

• C 4 → 2 → 1 → 3

• D 4 → 3 → 2 → 1

The diagram represents a simple reflex arc.

• A

• B

• C

• D

The diagram shows a neurone. Which structures could be found at X and Y?

• A

• B

• C

• D

The diagram shows a section through an eye. Which structure controls how much light enters the pupil?

• A

• B

• C

• D

Four processes occur when impulses cross a synapse. P neurotransmitter diffuses across the gap Q neurotransmitter binds with receptors R impulse stimulates vesicles S release of neurotransmitter What is the correct sequence for these processes?

• A P → R → Q → S

• B R → P → Q → S

• C R → S → P → Q

• D S → Q → R → P