Answer/Explanation:
It results in offspring with genetic variation. 2 different mates must be used in sexual reproduction. This is because each person is different since cells are produced and combined differently in the original offsprings. If the two adults were exactly the same, the offspring would have the exact same cell traits. Likewise will be done for the offspring of the two adults. The genes may be similiar to the ones of the adults, but since combined it will not be an exact replica. In the long run sexual reproduction will result in an offspring with slightly different traits or genetic variation.