A scientist investigated the effect of substance X on the nerve endings of neurones.
The scientist counted mitochondria in microscope images. Every image showed the same volume of a nerve ending.
| Group | Mean number of mitochondria in each image |
|---|---|
| Control | 48 |
| Exposed to substance X | 12 |
Calculate the percentage decrease in the mean number of mitochondria after exposure to substance X.
Predict how exposure to substance X would affect the transfer of an impulse from one neurone to the next.
Explain your answer.
282 exam-style questions on AQA GCSE Biology 1.1 Cell structure, covering 1.1.1 Eukaryotes and prokaryotes, 1.1.2 Animal and plant cells, 1.1.3 Cell specialisation, 1.1.4 Cell differentiation, 1.1.5 Microscopy, and 1.1.6 Culturing microorganisms. Each one has a worked solution and a mark scheme showing where the marks go.