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Selective breeding and GM

Selective breeding

These are the steps in selective breeding:

  1. Decide which characteristics are important
  2. Choose parents that show these characteristics
  3. Select the best offspring from parents to breed the next generation
  4. Repeat the process continuously

Examples of selective breeding


Producing disease-resistant wheat by crossbreeding wheat plants with disease resistance and wheat plants with a high yield.

Dairy cattle

Increasing milk yield by selecting bulls from high yield herds and breeding them with cows that have the best milk production.

Cattle breeds

Selective breeding can also be used to modify other characteristics of cattle.

Aberdeen Angus bull

Aberdeen Angus bull - bred for beef

Problems with selective breeding - higher tier

Future generations of selectively bred organisms will all share very similar genes. This could make some diseases more dangerous as all the organisms would be affected. Also there's increased risk of genetic disease caused by recessive genes.

Some genes would be lost, making it more difficult to produce new varieties in the future. In scientific language this would be described as ‘inbreeding can lead to a reduction in the size of the gene pool’.

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