Exam Focus

Exam Focus

Variation is tested regularly in AQA Paper 2 and Edexcel 1BI0/1 (Paper 1), often as shorter questions and as context for longer evolution questions. Common question formats:

• Classify variation type: Given an example (e.g., blood group, height), state whether it is continuous or discontinuous and whether it is genetic, environmental, or both.
• Graph interpretation: Describe the pattern shown in a histogram (normal distribution = continuous variation; separate bars = discontinuous variation).
• Explain sources of variation: Name and explain three causes — mutations, sexual reproduction (meiosis and random fertilisation), and environmental factors.
• Link to evolution: Variation questions often connect to natural selection — "explain why variation is important for natural selection" (variation provides the raw material for selection to act on).

Edexcel 1BI0 style: Edexcel Paper 1 (1BI0/1) often uses a data table or bar chart as stimulus — for example, measurement data for height, hand span, or reaction time from a class investigation. You may be asked to identify whether the data shows continuous or discontinuous variation, and to "Suggest" reasons for the distribution pattern. Extended questions link variation to natural selection and evolution — Edexcel expects you to make this connection explicitly rather than treating variation as a standalone topic.

Command word alert: "Describe the pattern" when given a graph = state whether it is a normal distribution (continuous) or separate categories (discontinuous). "Explain why" = give the biological reason for the pattern.