Selective breeding and tissue culture — Edexcel GCSE Biology
How selective breeding changes food plants and domesticated animals, and how tissue culture makes identical plants and cells.
Revision notes
2 short notes, 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.
Tissue culture
Triple onlyTissue culture is growing new cells or tissues from small pieces of tissue, using aseptic technique and a sterile nutrient medium containing nutrients and growth hormones. In plant breeding it quickly produces many plants that are genetically identical to the parent, so desirable characteristics are kept. In medical research it provides identical cells for testing new drugs.
Exam questions
6 exam-style questions (15 marks), each with its mark scheme.
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9 cards: flip them, mark what you knew, and practise the rest.
Practise the cardsMind map
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.
What are the advantages of tissue culture?
Triple only Tissue culture quickly produces many genetically identical plants from a very small amount of tissue, so useful characteristics are copied exactly. Plants can be produced all year round in a small space, and rare plants can be saved. In medical research, it gives large numbers of identical cells for testing new drugs.
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 Biology (1BI0) specification · Updated October 2026