Those changes in an individuals' genotype that ensure genetic variation begin to be done in Metaphase, where chromosomes are aligned to the equatorial axis of the cell, and eventually, each chromosome is pulled to each pole of the cell during Anaphase I. After this process, follows telophase I, where we can say that each chromosome is given to each of the two daughter cells. We can say then that the creation of different versions of alleles begins with Telophase I.
The answer is petiole. Hope this helps!!!
