Humans choosing and breeding only desirable characteristics in animals. This mimics natural selection - Humans determine what alleles are passed on instead of the enviroment
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Why is artificial selection used?
To obtain organisms with the characteristics that humans require
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Why may it take a long time?
Organisms with the required characteristics may not be developed straight away
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What does it produce?
Organisms of the same species known as different breeds/varieties
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What are the 2 methods of artificial selection?
Inbreeding and Outbreeding
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What is inbreeding?
The gametes of close relative fuse
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What is an issue of inbreeding?
Promotes homozygosity - Increases the chance of a harmful recessive gene being expressed - Known as inbreeding depression
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How can this issue be combatted?
Introduce new genes by outbreeding
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What is outbreeding?
Crossing unrelated varieties
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What is the benefit of outbreeding?
Promotes heterozygosity - Introduces hybrid vigour - New sets of chromosomes are complimentary in their effects
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Example - Milk Yield in Cattle
Select cow with highest milk yield > Select bull descended from cow with high milk yield > Cross the cow and the bull > Wait for female cows to mature and check milk yield > Select cow with highest yield > Repeat over several generations
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Other cards in this set
Card 2
Front
Why is artificial selection used?
Back
To obtain organisms with the characteristics that humans require
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