Reproduction sexual results in offspring with greater genetic wariation
Sexual reproduction gives greater variability because it allows the offspring to inherit chromosomes and genes from both parents producing random combinations of characters. In meiosis half of chromosomes corresponds to the mother and half to the father; therefore, half of the chromosomes are paternal and half are maternal. Another source of variation by chromosomal combination in meiosis is crossing-over where the combination occurs between the maternal and paternal chromosomes, but is performed within each pair of homologues, multiplying the types of gametes that are formed.
On the other hand, mitosis or asexual reproduction produces identical organisms, so the genetic variation is very low.