A student measures the heights of plants grown from seeds. All plants receive the same amount of water and light, but their heights differ. The student repeats the investigation using genetically identical cuttings and finds a smaller range of heights.
Which conclusion is best supported?
The cuttings show that environmental effects on height are impossible.
The seedlings show that plant height is controlled by one gene.
All variation in the seedlings was caused by new mutations.
Inherited differences probably contributed to the wider range in seedlings.
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.