If megaspore mother cell contains 10 pairs of homologous chromosomes than total how many chromosomes will be present in monospore embryo sac? Please solve.

In themonosporic embryo sac, meiosis of the diploid megaspore mother cell in the nucellus produces four haploid megaspores. Three of the megaspores, usually those at the micropylar end of the nucellus, subsequently undergo programmed cell death, leaving only one functional megaspore So here Megaspore mother cell has 10 pairs i.e.- 20 chromosomes so functional megaspore (n) in embryo sac will have 10 chromosomes. This functional megaspore will undergo 3 mitotic divisions thus resulting in total 8 nuclei each having 10 chromosomes only.