A student measures the time taken to press a button after seeing a light. The results are shown in the table.
Table
| Trial | Time / s |
|---|---|
| 1 | 0.24 |
| 2 | 0.22 |
| 3 | 0.26 |
Which statement gives the mean time and identifies the effector that presses the button?
0.72 s0.72\ \text{s}0.72 s and a finger muscle
0.24 s0.24\ \text{s}0.24 s and a finger muscle
0.24 s0.24\ \text{s}0.24 s and a light receptor
0.72 s0.72\ \text{s}0.72 s and a light receptor
111 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.