Scientists studied pairs of twins to find out how genes and the environment affect height and body mass.
The Table shows the results.
Table
| Type of twins | Mean difference in height in cm\text{cm}cm | Mean difference in body mass in kg\text{kg}kg |
|---|---|---|
| identical, raised together | 1.7 | 1.9 |
| identical, raised apart | 1.8 | 4.5 |
| non-identical, raised together | 4.4 | 4.6 |
Explain why studying identical twins who were raised apart is useful for finding out the effect of the environment.
A student concludes:
'Body mass is affected more by the environment than height is.'
Evaluate this conclusion. Use data from the Table.
Height shows continuous variation.
Explain why height does not fall into distinct groups.
Suggest one reason why the results for identical twins raised apart may not show the full effect of the environment.
186 exam-style questions on OCR GCSE Biology 5.1 Inheritance, covering 5.1.1 The genome, 5.1.2 Environment and phenotype, 5.1.3 Variants and mutations, 5.1.4 How genetic variants influence phenotype, 5.1.5 Asexual and sexual reproduction, 5.1.6 Haploid and diploid, 5.1.7 Meiotic cell division, 5.1.8 Single gene inheritance, 5.1.9 Predicting single gene crosses, 5.1.10 Sex determination, 5.1.11 Multiple gene inheritance, and 5.1.12 Development of our understanding of genetics. Each one has a worked solution and a mark scheme showing where the marks go.