Q. During which meiosis division does ploidy reduction take place? And Does it ploidy reduction occur in mitosis?

In the cell division by meiosis ploidy reduction occurs in meiosis II Primarily taking as instance a 2n somatic cell ploidy increases to 4n duplication of DNA during interphase. During meiosis I since homologous chromosomes are separated ploidy falls to 2n the original number and then during meiosis II ploidy finally falls to n in the resulting daughter cells.

Ploidy reduction does not take place in mitosis. This fact shows that, although in meiosis ploidy is decreased from its original number in meiosis II a process similar to mitosis the cause of that reduction is what happens in meiosis I that is the separation of the homologous chromosomes.