Inheritance & EvolutionExam Focus

Exam Focus

Part of VariationGCSE Biology

This exam focus covers Exam Focus within Variation for GCSE Biology. Genetic and environmental variation in organisms It is section 8 of 10 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.

Topic position

Section 8 of 10

Practice

25 questions

Recall

20 flashcards

Exam Focus

Regularly Examined

Variation is tested regularly in AQA Paper 2, 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).

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.

Keep building this topic

Read this section alongside the surrounding pages in Variation. That gives you the full topic sequence instead of a single isolated revision point.

Practice Questions for Variation

What is the main difference between genetic variation and environmental variation?

  • A. Genetic variation is caused by differences in DNA, environmental variation is caused by external factors
  • B. Genetic variation affects all organisms equally, environmental variation affects each organism differently
  • C. Genetic variation is reversible, environmental variation is permanent
  • D. Genetic variation only affects physical traits, environmental variation only affects behavioral traits
1 markfoundation

Explain how mutations contribute to genetic variation in populations.

4 marksstandard

Quick Recall Flashcards

What are the two main causes of genetic variation?
1. Mutations — random changes to DNA that create new alleles. 2. Sexual reproduction — combines alleles from two parents in unique combinations, producing offspring different from both parents.
What is variation in biology?
Differences in characteristics between individuals of the same species. Variation can be due to differences in genes (genetic variation), the environment, or a combination of both.

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