An enzyme in the petals of a plant produces a red pigment.
Plant A has a genetic variant in the non-coding DNA in front of the gene for this enzyme. Plant A has pale pink flowers.
Plant B has a genetic variant in the coding DNA of the gene for this enzyme. Plant B has white flowers.
Explain why plant A has pale pink flowers.
Explain why plant B has white flowers.
Plant C also has a genetic variant in the coding DNA of this gene, but it has red flowers.
Suggest one reason why.
44 exam-style questions on Edexcel GCSE Biology 3.2 DNA and protein synthesis, covering 3.2.1 DNA structure as a polymer, 3.2.2 Genome and gene definitions, 3.2.3 Extracting DNA from fruit, 3.2.4 Base order determines protein shape, 3.2.5 Stages of protein synthesis, 3.2.6 Non-coding DNA variants affecting phenotype, and 3.2.7 Coding DNA variants affecting phenotype. Each one has a worked solution and a mark scheme showing where the marks go.