Selective breeding and tissue culture — Edexcel GCSE Combined Science
How selective breeding is used to develop food plants and domesticated animals, and the benefits and problems it brings.
Revision notes
1 short note, in the order of the specification. Each one in short:
Selective breeding is when humans choose organisms with desired characteristics, such as high milk yield or disease resistance, and breed them together. The offspring with the characteristic are selected and bred again, over many generations, until it is strongly shown. It increases yields, but it reduces genetic variation, so a new disease could affect the whole population.
Exam questions
3 exam-style questions (8 marks), each with its mark scheme.
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The whole of natural selection and genetic modification on one page, so you can see where this subtopic fits.
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Quick check questions
What is selective breeding?
Show answer
Choosing parents with desired characteristics to breed together, and repeating this over many generations.
Name two characteristics selected for in food plants.
Show answer
Any two of: disease resistance, larger fruit or grains, better taste, higher yield.
Why can selective breeding be a risk to a population?
Show answer
It reduces genetic variation, so a new disease or change could affect all individuals.
Frequently asked questions
What is selective breeding in plants?
Selective breeding in plants is when humans choose plants with a desired characteristic, such as disease resistance, larger fruit or higher yield, and breed them together. The offspring with the characteristic are selected and bred again, over many generations, until it is strongly shown. This produces more food from the same land.
What are the disadvantages of selective breeding?
The main disadvantage of selective breeding is that breeding from only a few individuals reduces genetic variation. If a new disease or a change in the environment appears, all the individuals may be affected and the population could die out. Inbreeding can also make harmful inherited conditions more common in domesticated animals.
How long does selective breeding take?
Selective breeding takes many generations. Parents that show the characteristic most strongly are bred together, then the offspring with the characteristic are selected and bred, and this is repeated until the characteristic is strongly shown. Because of this, it is slower than genetic engineering, which changes the genome directly.
Written and checked against the Edexcel GCSE Combined Science (1SC0) specification · Updated October 2026