During meiosis I, as the name reductional division implies, the chromosome number is reduced from diploid (2n) to haploid (1n), and the amount of DNA is reduced from the (4d) to (2d). During prophase I, double-stranded chromosomes condense, and homologous chromosomes (normally one inherited from the mother and one from the father) are paired at centromeres. At this point, recombination of genetic material between the maternal and paternal chromosome pairs may occur. In metaphase I, the homologous chromosomes with their centromeres line up along the equator of the mitotic spindle and in anaphase I are separated and distributed to each daughter cell. This results in reduction of both the chromosome number (1n) and the DNA to the (2d) amount.
No DNA replication precedes meiosis II. The division during meiosis II is always equatorial because the number of chromosomes does not change. It remains at (1n), although the amount of DNA represented by the number of chromatids is reduced to (1d). During metaphase II, each chromosome aligns along the equator of the mitotic spindle, and at anaphase II sister chromatids are separated from each other. Thus, each chromosome splits into two single-stranded chromosomes that are then distributed to each haploid daughter cell.
Phases in the process of meiosis are similar to the phases of mitosis.
The prophase of meiosis I is an extended phase in which pairing of homologous chromosomes, synapsis (close association of homologous chromosomes), and recombination of genetic material on homologous chromosomes is observed. Prophase I is subdivided into the following five stages (see Fig. 3.12).
 Leptotene. This stage is characterized by the condensation of chromatin and by the appearance of chromosomes. Sister chromatids also condense and become connected with each other by meiosisspecifc cohesion complexes (Rec8p). At this phase, pairing of homologous chromosomes of maternal and paternal origin is initiated. Homologous pairing can be described as a process in which chromosomes actively search for each other. After finding their mates, they align themselves side by side with a slight space separating them.
 Zygotene. Synapsis, the close association of homologous chromosomes, begins at this stage and continues throughout pachytene. This process involves the  formation of a synaptonemal complex, a tripartite structure that binds the chromosomes together. The synaptonemal complex is often compared to railroad tracks with an additional third rail positioned in the middle between two others. The cross ties in this track are represented by the transverse filaments that bind the scaffold material of both homologous chromosomes together.
 Pachytene. At this stage, synapsis is complete. Crossing-over occurs early in this phase and involves transposition of DNA strands between two different chromosomes.
 Diplotene. Early in this stage, the synaptonemal complex dissolves, and the chromosomes condense further. Homologous chromosomes begin to separate from each other and appear to be connected by newly formed junctions between chromosomes called chiasmata (sing., chiasma). Sister chromatids still remain closely associated with each other. Chiasmata indicate that crossing-over may have occurred.
 Diakinesis. The homologous chromosomes condense and shorten to reach their maximum thickness, the nucleolus disappears, and the nuclear envelope disintegrates.