Scientists studied four pairs of identical twins who had grown up in different homes. The twins within each pair had the same alleles, but the different pairs were not genetically identical.
Health records showed that one twin in each pair had an adequate diet during growth and the other had a limited diet. Other conditions that could affect growth were as similar as possible.
| Pair of twins | Adult height with adequate diet in cm | Adult height with limited diet in cm |
|---|---|---|
| 1 | 178 | 169 |
| 2 | 165 | 157 |
| 3 | 183 | 174 |
| 4 | 172 | 164 |
Explain what the results suggest about the causes of variation in adult height.
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.