Damage to one cerebral hemisphere can cause a loss of voluntary movement of one hand. Researchers tested two treatments, A and B, on two groups of patients with this damage. In both treatments, transplanted stem cells developed into replacement neurones.
The table shows the results six months after each treatment.
| treatment | replacement neurones surviving (%) | surviving replacement neurones forming connections with existing neurones (%) | mean number of successful hand movements in 20 attempts |
|---|---|---|---|
| A | 86 | 12 | 3 |
| B | 61 | 68 | 15 |
Evaluate which treatment should be selected for a larger trial.
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.