6.2.3: Selective breeding
Not started yet — this one needs some love.
Selective breeding: the process by which humans breed plants and animals for particular genetic characteristics.
Humans have used selective breeding for thousands of years in food crops and domesticated animals.
The process:
choose parents with the desired characteristic from a mixed population and breed them together
breed together the offspring that show the desired characteristic
repeat over many generations until all the offspring show it
Useful selected characteristics include:
disease resistance in food crops
animals that produce more meat or milk
domestic dogs with a gentle nature; large or unusual flowers
Selective breeding can lead to inbreeding, where some breeds are particularly prone to disease or inherited defects.
Common exam mistakes
Do not write only "repeat"; say that offspring with the desired characteristic are selected and bred over many generations.
Select offspring with the desired characteristic from each generation; do not keep re-breeding only the original parents.
Do not confuse selective breeding with genetic engineering: selective breeding uses breeding, genetic engineering modifies the genome.