How fast can you react? — questions

1. identify

Which list contains only parts of the central nervous system (CNS)?

Circle one answer.

• The brain and the spinal cord.
• The brain, the spinal cord and the arm nerves.
• The spinal cord and the backbone.
• The brain only, with nothing else.

Nudge (only if you are stuck): The CNS lies along the middle of the body: in the head and inside the backbone.

2. identify

In what form does a message travel along a neurone?

Circle one answer.

• As a liquid flowing along inside the cell.
• As a hormone carried along inside the cell.
• As a chemical diffusing along the cell.
• As electrical impulses passing along the cell.

Nudge (only if you are stuck): Think of a signal passing along the cell, not of a substance moving.

3. identify

Sort each part of the nervous system into the central nervous system (CNS) or the peripheral nervous system (PNS).

Write the number of the matching option.

1. PNS
2. CNS

• the brain: ______
• the spinal cord: ______
• a nerve in the leg: ______
• a nerve from the tongue to the brain: ______

Nudge (only if you are stuck): Is the part inside the brain or the spinal cord, or outside them?

4. identify

Your phone buzzes on the table and you pick it up. Match each word to the right part of this response.

Write the number of the matching option.

1. sound-sensitive cells in the ear
2. muscles in the arm and hand
3. the sound of the buzz

• stimulus: ______
• receptor: ______
• effector: ______

Nudge (only if you are stuck): Which part is the change, which part detects it, and which part moves?

5. determine

A pupil catches a falling metre rule at the 30 cm mark. Use the table to determine the reaction time for this catch.

Reaction time: ______________ unit ________

Nudge (only if you are stuck): Find 30 cm in the distance column.

6. calculate

A pupil's five reaction times are 0.20 s, 0.22 s, 0.19 s, 0.21 s and 0.18 s. Calculate the mean reaction time.

Mean reaction time: ______________ unit ________

Nudge (only if you are stuck): Add the five times, then divide by how many there are.

7. explain

One nerve in your arm carries impulses towards your hand and away from it at the same time. Explain how one nerve can do this.

Nudge (only if you are stuck): How many neurones are in a nerve, and do they all carry impulses the same way?

8. identify

You feel a small stone inside your shoe, so you decide to reach down with your hand and take it out. Which row describes the path of the impulses correctly?

Circle one answer.

• A
• B
• C
• D

Nudge (only if you are stuck): Follow the nerves of the leg. Where do they join the CNS, and where is a choice made?

9. calculate

A pupil catches a falling metre rule at 24, 27, 22, 30 and 22 cm. Use the table to turn each catch into a time, then calculate the mean reaction time. Give your answer to 2 decimal places.

Mean reaction time: ______________ unit ________

Nudge (only if you are stuck): Turn every distance into a time first, then find the mean of the times.

10. explain

Two pupils compare their reaction times with a falling metre rule. Pupil P starts each drop with the 0 cm mark level with the top of the thumb. Pupil Q starts each drop with the 5 cm mark level with the top of the thumb, but reads the mark at the thumb in the same way. Explain why the table gives Q times that are too long.

Nudge (only if you are stuck): At the start, which mark is already level with Q's thumb?

11. explain

You walk out of a cool shop into hot sunshine and start to sweat more. When you go back inside, you sweat less again. Explain how this shows the nervous system regulating a body function.

Nudge (only if you are stuck): Regulation means keeping something at the right level as conditions change. What is kept at the right level here?

12. identify / explain / calculate

A pupil catches a falling metre rule at 15, 18, 31, 14 and 16 cm. (a) Identify the anomalous catch, and explain why the 18 cm catch is not anomalous. (b) The pupil does the anomalous catch again and gets 17 cm. Use the table to calculate the mean reaction time of the five catches they now use. Give your answer to 2 decimal places.

(a) Anomalous catch, and why not 18 cm

(b) Mean reaction time

Nudge (only if you are stuck): Which catch is far from all the others, and which is only a little slower than the rest?

13. state / explain

A goalkeeper sees a ball flying towards the goal and dives to stop it. (a) State the stimulus, one receptor and the effectors. (b) Explain why this response needs coordination.

(a) Stimulus, receptor, effectors

(b) Why coordination

Nudge (only if you are stuck): Many muscles have to act together, at the right moment.

14. identify

Two pupils, F and G, each catch a falling metre rule five times. Their times, in seconds, are F: 0.17, 0.24, 0.23, 0.25, 0.24 and G: 0.21, 0.19, 0.18, 0.20, 0.19. Pupil F says: "My first catch was faster than G's first catch, so I react faster than G." Which row is correct?

Circle one answer.

• A
• B
• C
• D

Nudge (only if you are stuck): Compare the two pupils on all five catches, not on one.

15. identify

One neurone can lie partly in the CNS and partly in the PNS. Sort each part into the central nervous system (CNS) or the peripheral nervous system (PNS).

Write the number of the matching option.

1. PNS
2. CNS

• the cell body of a motor neurone, inside the spinal cord: ______
• the long fibre of that motor neurone, running down the leg to a muscle: ______
• the fibre of a sensory neurone, running from the skin of the arm towards the spinal cord: ______
• a short neurone that lies wholly inside the brain: ______

Nudge (only if you are stuck): For each part, ask: is it inside the brain or the spinal cord, or outside them?