A botanic garden is reviewing a conservation programme for a rare annual plant.
A seed collection from one wild population was divided between two glasshouses. The plants were kept in separate glasshouses for 120 generations, with no transfer of pollen or seeds between them.
| Plant group | Glasshouse conditions | Frequency of allele A in generation 1 | Frequency of allele A in generation 120 | Plants with allele A that survived to produce seeds | Plants without allele A that survived to produce seeds |
|---|---|---|---|---|---|
| C | Cool and damp | 48% | 81% | 68% | 34% |
| D | Warm and dry | 48% | 17% | 29% | 63% |
Scientists then carried out cross-pollination trials.
| Pollen source and ovule source | Number of crosses | Crosses that produced offspring | Crosses that produced fertile offspring |
|---|---|---|---|
| C and C | 30 | 25 | 22 |
| D and D | 30 | 24 | 21 |
| C and D | 30 | 20 | 0 |
Using the records, explain how natural selection caused plant groups C and D to become genetically different.
The botanic garden proposes transferring pollen between groups C and D to increase the number of plants able to reproduce in future generations. Evaluate this proposal.
71 exam-style questions on AQA GCSE Biology 6.3 The development of understanding of genetics and evolution, covering 6.3.1 Theory of evolution, 6.3.2 Speciation, 6.3.3 The understanding of genetics, 6.3.4 Evidence for evolution, 6.3.5 Fossils, 6.3.6 Extinction, and 6.3.7 Resistant bacteria. Each one has a worked solution and a mark scheme showing where the marks go.