Every organism is unique, even though the nucleotides making up DNA are all the same, because the structure is different in every organism. In other words, it's just the order in which nucleotides are placed that differs each organism from one another.
It spread by person to person
Consumer is a person who purchases
Producer is someone that makes the things consumers purchase
The benefits of artificial selection is that you've taken the traits that you desire from a plant or an animal that could benefit your own survival. (Much like our ancestors bred the highest/most efficient crops, leaving us in a good farming position today). However, the drawbacks of artificial selection is that you effectively destroy any natural selection or "survival of the fittest" thus reducing the gene pool. If a virus or bacteria was effective against a crop that we bred, it would destroy our entire farming industry (also works with animals that we breed).