Identify a reason why meiosis leads to significant genetic variation while mitosis does not.

Because meiosis only has half of the genes.

In mitosis, the cell produced will have an exact number of chromosome like the parent cells. But in meiosis, only half of the chromosome will be given. That will make many variations since the chromosome is split in random. The process to split the gene doesn't include a process to making it move in the same manner so the gene position can be changed in the different case.