A newly identified animal species, X, has a flattened body. Scientists first grouped species X with species Y because species Y also has a flattened body.
Scientists then compared species X with species Y and species Z.
| Comparison | Matching internal structures out of 12 examined | Differences in a corresponding DNA sequence of 500 bases |
|---|---|---|
| species X and species Y | 3 | 42 |
| species X and species Z | 10 | 8 |
Use the data to explain whether the original classification of species X should be changed.
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.