A microorganism, X, was first classified as a bacterium because its cells had the same shape as cells of reference bacterium B. Scientists later compared microorganism X with reference archaeon A and reference bacterium B.
| Evidence | Reference archaeon A | Reference bacterium B |
|---|---|---|
| Cell shape compared with X | Different | Same |
| Percentage of bases that match X in selected DNA sequences | 81% | 43% |
| Pattern of cell molecules compared with X | Very similar | Different |
Using the data, explain why scientists should revise the classification of microorganism X.
81 exam-style questions on AQA GCSE Biology 6.4 Classification of living organisms, covering 6.4 Classification of living organisms. Each one has a worked solution and a mark scheme showing where the marks go.