A conservation centre wants to increase the number of animals in a rare horse breed. The centre plans to produce four genetically identical foals and place each developing embryo into a different host mare.
A researcher proposes fertilising four egg cells from one mare using sperm cells from one stallion. Each embryo would then be placed into a host mare.
Explain why this procedure would not produce four cloned foals. Describe one correction that would allow clones to be produced.
After the procedure is corrected, the host mares eat different mean masses of food each day during pregnancy.
The table shows the results.
| Mean mass of food eaten by the host mare each day in kg | Birth mass of foal in kg |
|---|---|
| 7.0 | 42 |
| 7.5 | 45 |
| 8.0 | 48 |
| 8.5 | 51 |
Using the data, explain why the cloned foals have different birth masses. Predict the birth mass of a cloned foal carried by a host mare that eats 9.0 kg of food each day.
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.