Clones of two plant genotypes are grown at two temperatures. Other conditions are controlled.
Table: Mean plant height after eight weeks
| Genotype | At 15 ∘C\,^\circ\text{C}∘C / cm | At 25 ∘C\,^\circ\text{C}∘C / cm |
|---|---|---|
| R | 18 | 30 |
| S | 24 | 28 |
Which conclusion is supported by these results?
Genotype R is taller than genotype S at both temperatures.
The effect of temperature on height differs between the genotypes.
The two genotypes respond equally to the change in temperature.
Temperature affects height but genotype has no effect on height.
40 exam-style questions on Edexcel GCSE Biology 3.4 Variation and the Human Genome Project, covering 3.4.1 Causes of variation, 3.4.2 Outcomes of the Human Genome Project, 3.4.3 Genetic variation within a population, and 3.4.4 Effects of genetic mutations on phenotype. Each one has a worked solution and a mark scheme showing where the marks go.