The table shows how long ago each pair of four salt-marsh plant species, A, B, C and D, last shared a common ancestor. In the evolutionary tree for these species, every branch point divides one lineage into exactly two.
| Pair | Time / million years |
|---|---|
| A and B | 6 |
| A and C | 14 |
| A and D | 14 |
| B and C | 14 |
| B and D | ? |
| C and D | 2 |
What is the missing time for B and D, and which pair of species is most closely related?
6 million years; A and B are most closely related.
14 million years; A and B are most closely related.
6 million years; C and D are most closely related.
14 million years; C and D are most closely related.
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.