A student investigated two types of response.
Response 1: the knee-jerk reflex, measured when the knee is tapped.
Response 2: catching a ruler that is dropped without warning.
The Table shows the results.
Table
| Trial | Time for knee-jerk reflex in s\text{s}s | Time to catch the ruler in s\text{s}s |
|---|---|---|
| 1 | 0.05 | 0.24 |
| 2 | 0.04 | 0.21 |
| 3 | 0.06 | 0.23 |
| 4 | 0.05 | 0.20 |
| 5 | 0.05 | 0.22 |
Calculate the mean time to catch the ruler.
Calculate how many times longer it takes to catch the ruler than to carry out the knee-jerk reflex.
Use a mean time of 0.05 s for the knee-jerk reflex.
Explain why catching the ruler takes longer than the knee-jerk reflex.
Give one variable that the student should control in this investigation.
43 exam-style questions on Edexcel GCSE Biology 2.3 The nervous system and brain, covering 2.3.1 Structures and functions of the brain, 2.3.2 Imaging brain function with scanning, 2.3.3 Limitations in treating nervous system damage, 2.3.4 Neurones and impulse transmission, and 2.3.5 Structure and function of a reflex arc. Each one has a worked solution and a mark scheme showing where the marks go.