A scientist classifies four species of freshwater insect using body colour.
| Group | Species | Body colour |
|---|---|---|
| 1 | J and K | green |
| 2 | L and M | brown |
The scientist compares the same region of DNA from each species.
| Species compared | Number of base differences |
|---|---|
| J and K | 72 |
| J and L | 10 |
| J and M | 66 |
| K and L | 69 |
| K and M | 12 |
| L and M | 64 |
Using the data, explain one disadvantage of the scientist's classification and suggest how the species should be grouped into two pairs in a natural classification system.
122 exam-style questions on OCR GCSE Biology 5.2 Natural selection and evolution, covering 5.2.1 Genetic variation within a population, 5.2.2 Developments in classification systems, 5.2.3 How evolution occurs through natural selection, 5.2.4 Evolution as change over time, 5.2.5 Evidence for evolution, and 5.2.6 Darwin and Wallace. Each one has a worked solution and a mark scheme showing where the marks go.