Yarrow is a species of plant that grows in lowland areas and in mountain areas.
Scientists collected seeds from a lowland population and from a mountain population. They grew some of each type of seed in its original area and some in the same lowland garden.
The Table shows the results.
Table
| Origin of seeds | Mean height when grown in original area in cm | Mean height when grown in lowland garden in cm |
|---|---|---|
| lowland population | 80 | 78 |
| mountain population | 20 | 35 |
Explain what these results show about the causes of variation in the height of yarrow plants.
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.