Variation produced by Meiosis
In Meiosis I members of homologous pairs separate during anaphase. The separation of each pair is random with all the other pairs.r. Therefore the orientation of each chromosome pairs is random with rother chromosome pairs. This is necessary for the independent assortment of genes, an important principle of genetics. It also allows for gametes, and offspring, to be much more genetically variable than they would be if all the paternal and maternal chromosomes were inherited as a unit.
In human all reproduction is sexual. It involves joining together haploid gamete cells from each parent with half the normal number of chromosome to make a new cell containing both parents genetic material. This is a diploid zygote.
when a cell divides, it make a copy of its DNA and sometimes the copy is not quite perfect. That small difference from the original DNA sequene is a mutation. Mutations can also be caused by exposure to specific chemicals or radiation. This agents cause the DNA to break down.