A breeder wants to produce a population of goats with a high milk yield. Four possible breeding plans are shown.
For each male goat, the table gives the milk yield of its mother.
| Breeding plan | Mean milk yield of female goats in litres per day | Milk yield of male goat's mother in litres per day | Is the male closely related to the females? |
|---|---|---|---|
| A | 4.2 | 4.3 | Yes |
| B | 4.0 | 4.1 | No |
| C | 2.5 | 4.4 | No |
| D | 4.4 | 2.4 | No |
Use the information in the table to suggest which breeding plan the breeder should use. Explain how repeatedly selecting offspring from this plan could increase milk yield while reducing the risk of inherited defects.
80 exam-style questions on AQA GCSE Biology 6.2 Variation and evolution, covering 6.2.1 Variation, 6.2.2 Evolution, 6.2.3 Selective breeding, 6.2.4 Genetic engineering, and 6.2.5 Cloning. Each one has a worked solution and a mark scheme showing where the marks go.