they arose by artificial selection. this is because to obtain animal with this traits, there is an interference by humans. i.e these organisms do not result from natural selection. the process of obtaining organisms with increased number of desirable traits is referred to as hybrid vigor. in this process an animal with certain desirable trait is bred with another animal with another different type of desirable trait. the resulting offspring will have both desirable traits.
Answer:
1 . advantages faster and more certain method of propagation neural produce exactly identical quantities and the parent the space of the characteristic of food and power crop
2. does not produce new varieties leads to overcrowding around the parent plant
