Answer
The reason for greater genetic variation in sexual reproduction than asesxual is primarily due to the behaviour of chromosomes during meiosis and fertilization.The various mechanisms that contribute to this variation include:
1)recombination or crossing over of homologous chromosomes
2)independent assortment of chromosomes and
3)random fertilisation.
Work Step by Step
1)Recombination or crossing over:It is the process by which alleles on maternal and paternal chromosomes mix up, thus giving
rise to combinations of alleles not present in either parental
chromosome. These novel combinations of alleles are the basis of
novel combinations of traits among offspring of sexual reproducing organisms.
2)Independent assortment of chromosomes:It is the process by which homologous chromosomes are randomly distributed to daughter cells, and different chromosomes segregate independently of each other during meiosis. This results in new combinations of genes on each chromosome.
3)Random fertilisation:This type of fertilization of the gametes also ensures variation as any of the genetically unique sperm generated by a male may fertilize the genetically unique egg produced by a female.
