B3 - Selective Breeding Flashcards
Process of selective breeding?
1) from existing stock select organisms with desirable features.
2) breed them together.
3) select the best from offspring and breed them together.
4) do this over several generations and the desirable features get stronger and stronger.
What features are organisms usually selectively bred for?
Maximum yield of milk, meat, grain.
Good health and disease resistant.
Temperament, speed, attractiveness.
Why is there a reduced gene pool in selectively bred organisms?
Because you breed closely related organisms as they have the desirable feature which cause inbreeding causes a shortage of different alleles and therefore a small gene pool.
Why is disease more likely in selectively bred organisms?
Genetic disorders are usually recessive but when you keep breeding closely related organisms then recessive alleles are more likely to build up in population so disease is more common
Why is there a problem is a disease does build up in a selectively bred population?
They don’t have much variation so if one gets killed because their immune system cannot deal with it then the others are likely to die as well as thy would have similar immune system.
