4.3.9(Natural selection ad evolution)

Describe the process of natural selection

• Mutations occur in organisms which create more alleles

• When a selection pressure is applied, individuals with an advantageous allele will survive

• These individuals can then reproduce and pass on their advantageous alleles

• After many generations, there will be an increase in the advantageous allele frequency in the population

Describe the implications for humans for pesticide resistant insects

• Crops infested with pesticide-resistant insects are hard to control

• until the farmer finds a pesticide that will kill the insect, the crop will continue to be damaged

• Pesticide-resistant mosquitoes could increase the spread of disease

Describe the implications for humans for drug resistant microorganisms

• Pathogens have evolved resistant to drugs too

• Some Protoctista that cause malaria are resistant to several antimalarial drugs

• This means that new drugs need to be developed - this takes a lot of time and costs a lot of money

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