B6: Selective Breeding Flashcards
What is selective breeding?
When humans artificially select the plants or animals that are going to breed so that the genes for particular characteristics remain in the population.
Why are organisms selectively bred?
To develop feature that are useful or attractive
Give a few examples of where selective breeding is used
Animals that produce more meat or milk
Crops with disease resistance
Dogs with a good, gentle temperament
Decorative plants with big or unusual flowers
What is the basic process involved in selective breeding?
1) stock with the desired characteristics are selected
2) they’re then bred
3) the best of the offspring are chosen and bred together
4) this process is continued over several generations = the desirable trait gets stronger and stronger, eventually all offspring will have the characteristic
What is the main drawback of selective breeding?
A reduction in the gene pool- the farmer keeps breeding form the ‘best’ animals or plants, which are all closely related. This is known as inbreeding.
How can inbreeding cause health problems?
There’s more chance of the organisms inheriting harmful genetic defects when the gene pool is limited.
If a new disease occurs, why is inbreeding a serious problem?
Because there’s not much variation in the population; all the stock are related to each other, so if one of them is going to be killed by a new disease, it’s likely the others will also succumb to it.
