Give benifits and risks of selective breed.

Benifits: 1)new varieties may be economically important, by producing more or better quality food 2)animals can be selected that cannot cause harm, for example cattle without horns Risks: 1)reduced genetic variation can lead to attack by specific insects or disease, which could be extremely destructive 2)rare disease genes can be unknowingly selected as part of a positive trait, leading to problems with specific organisms, eg a high percentage of Dalmatian dogs are deaf 3)can create physical problems in specific organisms, eg large dogs can have faulty hips due to not being formed correctly