Selective breeding

What is the first step of selective breeding?

Deduce what characteristics are wanted, and select organisms with the desired characteristic from a mixed population

Then?

Breed them together, and from the offspring select those with the desired characteristics and breed them together. Continue over many generations to increase the frequency of the desired characteristics

Why might farmers want to do selective breeding in plants (three reasons)?

• Increase crop yield

• Disease resistant

• Hardiness to weather conditions

What are the problems of selective breeding?

Inbreeding occurs, which is when “best” animals or plants who are closely related breed, resulting in a reduction in the gene pool. This is a reduction of the number of alleles in a population, increasing the risk of organisms inheriting harmful genetic of being vulnerable to disease

What are the reasons for selective breeding in animals?

• Cows, goats and sheep that produce more milk or meat

• Chickens that lay large eggs

• Domestic dogs that have a gentle nature

3 difference between natural selection and selective breeding (artificial selection)

1. Natural selection occurs naturally, whereas artificial selection occurs when humans intervene

2. Natural selection results in the development of characteristics that are better adapted for survival, whereas artificial selection results in the development of characteristics that are more useful to humans, not beneficial for survival

3. Natural selection takes a long time to occur, whereas artificial selection takes less time