Chromosome segregation during mitosis and meiosis

How does the cell ensure that during cell division each daughter cell inherits one copy of every chromosome? Meiosis is a specialized cell division which produces haploid gametes from diploid cells, how is this reduction of chromosome number achieved? We want to understand how cells accurately segregate their chromosomes during mitosis and meiosis. It is important to understand this process because defects in chromosome segregation (missegregation) during mitosis result in cells with abnormal number of chromosomes. Such cells are hallmarks of cancer. Moreover, defects during meiosis cause miscarriages, infertility and genetic diseases such as Down’s Syndrome.