Answer:
Prophase I
Explanation:
Meiosis is the cellular division that produces the gametes and results in 4 haploid cells. Since these cells will go on to become the offspring, it's important for genetic variation.
Crossing-over is one contribution of genetic variation because it is where the homologous chromosomes exchange parts of their genes. In meiosis, it occurs in Prophase I.
Hope this helps!
