The main function of meiosis II is to separate the sister chromatids of each chromosome, resulting in four haploid daughter cells, each with half the number of chromosomes as the original diploid cell.

Here's a breakdown:

* Meiosis I separates homologous chromosomes, resulting in two haploid cells with duplicated chromosomes (still containing sister chromatids).

* Meiosis II then divides the sister chromatids of each chromosome, resulting in four haploid cells with a single copy of each chromosome.

Therefore, meiosis II is essential for producing gametes (sperm and egg cells) for sexual reproduction, ensuring that the offspring inherit one set of chromosomes from each parent.