Exam Focus

Exam Focus

Selective breeding questions are common in AQA Biology Paper 2 and Edexcel 1BI0/1 (Paper 1). These are the highest-value areas to revise:

• Describe the process (3-4 marks): Use the SSBR steps. Always include "over many generations" — this is a marking point in most mark schemes.
• Disadvantages — reduced gene pool (2-3 marks): State that genetic variation is reduced, explain that the whole population may be vulnerable to the same disease, and link this to lack of variety in alleles.
• Comparison with genetic engineering (4-6 marks): This is a classic evaluate question. Have clear points for both sides: speed, precision, ethical concerns, gene pool impact.
• Real-world example questions: You may be given a novel scenario (e.g., breeding a drought-resistant crop). Apply the SSBR process directly to that context — do not give a generic answer.

Edexcel 1BI0 style: Edexcel Paper 1 (1BI0/1) regularly uses a novel agricultural or horticultural scenario as stimulus — for example, a passage describing a breeding programme to improve disease resistance in wheat, or data on yield improvements in dairy cattle over decades. You are expected to apply the selective breeding process to the specific context. The command word "Suggest" is used when the scenario is unfamiliar. Edexcel extended responses on selective breeding vs genetic engineering require a balanced evaluation with a justified conclusion — one-sided answers do not reach the top band.