Compare sexual reproduction and asexual reproduction in terms of the genetic variation produced in offspring. Explain why sexual reproduction is advantageous to a species in a changing environment.

AQA GCSE Biology (8461) — 4.6.2 Variation and evolution · Compare · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Model answer (4 marks)

Sexual reproduction produces genetically varied, non‑identical offspring, whereas asexual reproduction produces genetically identical clones.
Variation in sexual reproduction arises because gametes from two parents combine at fertilisation.
In a changing environment, some variants are more likely to survive or be better adapted, so the species is less likely to become extinct.

Examiner tips

  • Use the words "genetically varied" and "clones" to hit the key points.
  • Explain the source of variation (gamete combination) to gain full marks.
  • Mention the survival advantage in a changing environment to complete the comparison.

Common mistakes

  • Saying that asexual reproduction also creates variation – it does not. Forgetting to state that variation comes from fertilisation of two gametes. Not linking variation to survival advantage in a changing environment.

Mark scheme (4 marks)

  1. Sexual reproduction produces genetically varied / non-identical offspring
  2. Asexual reproduction produces genetically identical offspring (clones)
  3. Variation in sexual reproduction arises because gametes from two parents are combined at fertilisation
  4. In a changing environment, some variants are more likely to survive / be better adapted, so the species is less likely to become extinct

Key terms in this question

sexual reproduction · asexual reproduction · genetic variation

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