A scientist tests a treatment intended to repair damaged myelin in a motor neurone. Electrical impulses are timed over the same 0.75 m section before and after treatment.
The mean transmission time over 0.75 m in motor neurones with intact myelin is also measured.
| Condition | Mean transmission time in s |
|---|---|
| Before treatment | 0.1500 |
| After treatment | 0.0075 |
| Motor neurones with intact myelin | 0.0060 |
Calculate the transmission speed after treatment as a percentage of the transmission speed in motor neurones with intact myelin.
Evaluate the scientist's conclusion that the treatment completely repaired the damaged myelin.
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.