Scientists discover two microorganisms, U and V. Both microorganisms lack a nucleus and appear as short rods when viewed using a microscope.
Scientists compare a section of DNA from each microorganism with the same section from reference organisms whose domains are known. A higher percentage similarity indicates that the microorganisms are more closely related.
| Microorganism | Similarity to bacterial reference organism (%) | Similarity to archaeal reference organism (%) |
|---|---|---|
| U | 92 | 58 |
| V | 61 | 95 |
Name the domain that is not represented by either reference organism in the table.
A scientist proposes that U and V should both be classified in Bacteria because neither microorganism has a nucleus.
Evaluate this proposal using the DNA data.
A second laboratory obtains different results for microorganism V.
| Microorganism | Similarity to bacterial reference organism (%) | Similarity to archaeal reference organism (%) |
|---|---|---|
| V | 94 | 62 |
Suggest how scientists should respond to the disagreement between the two laboratories.
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.