Meiosis consists of two divisions, meiosis I and meiosis II. The first division of meiosis is called heterotypic or reduction division. During this division the number of chromosomes is reduced to half. The two chromatids of a chromosome become genetically different due to crossing over. These chromatids are separated in the second division of meiosis. The second meiotic division is known as homotypic or equational division, because the chromosome number remains the same as produced after the end of the first division. Though meiosis II is similar to mitosis, meiosis II is not mitosis because (i) it always occurs in haploid cells, (ii) it is not preceded by DNA replication, (iii) the two chromatids of a chromosome are often dissimilar, (iv) the daughter cells formed after meiosis II are neither similar to each other nor similar to the parent cell.