Selective Breeding Flashcards
All 6 cards in this deck
What is selective breeding?
Choosing organisms with desired characteristics and breeding them together over many generations so the offspring show those characteristics.
What are the steps of selective breeding?
e.g. breeding cows for a higher milk yield
- Choose parents with the desired characteristic — cows with the highest milk yield
- Breed them together — take offspring from these parents
- Select the best offspring and repeat over many generations — milk yield increases each generation
Give two characteristics that food plants are commonly selectively bred for.
Higher crop yield and disease resistance.
True or false? Selective breeding introduces new genes into a species.
False. It only increases the frequency of alleles that are already present in the population.
State two problems caused by selective breeding.
Reduced genetic variation, and a greater chance of inherited defects/disease in the population.
How do breeding programmes try to maintain genetic variation?
By keeping breeding records/pedigrees to avoid breeding close relatives, and by using gene or sperm banks to reintroduce different alleles.