selective breeding Flashcards
1
Q
define selective breeding
A
the process by which humans breed plants and animals for specific genetic characteristics, which are often advantageous, through many generations
2
Q
describe selective breeding in animals
A
- individuals with the desired characteristics are bred together
- as a result, the genes for the desired characteristic are passed onto the offspring
- offspring that best express the desired characteristic are selected and bred together
- this process is repeated for many successive generations
3
Q
give 2 examples of when selective breeding might be used in animals
A
- cows, goats and sheep that produce a lot of milk
- chickens that lay large eggs
4
Q
describe selective breeding in plants
A
- plant species with the desired characteristics are chosen to cross pollinate and reproduce
- as a result, the genes for the desired characteristic are passed onto the offspring
- offspring that best express the desired characteristic are selected and bred together
- this process is repeated for many successive generations
5
Q
give 3 examples of when selective breeding might be used in plants
A
- disease resistance in food crops
- increased crop yield
- hardiness to weather conditions
6
Q
describe the problem with selective breeding
A
selective breeding can cause a reduction in the gene pool (a reduction in the number of different alleles in a population). this can lead to:
- organisms inheriting harmful genetic defects
- organisms being vulnerable to new diseases