Metaphase I

Homologous pairs move together along the metaphase plate: As kinetochore microtubules from both centrioles attach to their respective kinetochores, the homologous chromosomes align along an equatorial plane that bisects the spindle, due to continuous counterbalancing forces exerted on the bivalents by the microtubules emanating from the two kinetochores of homologous chromosomes. The physical basis of the independent assortment of chromosomes is the random orientation of each bivalent along the metaphase plate, with respect to the orientation of the other bivalents along the same equatorial line (see Fig 3).

Anaphase I

Homologous chromosomes are pulled apart by shortening of spindle fibres, each chromosome still containing a pair of sister chromatids. The cell then elongates in preparation for division down the center (see Fig 3).

Anaphase I

Chromosomes are at two different poles in the cell and the nuclear envelopes may reform, or the cell may quickly start meiosis II. Each daughter cell now has half the number of chromosomes but each chromosome consists of a pair of chromatids (see Fig 3).

Telophase I

The two daughter cell now has half the number of chromosomes but each chromosome consists of a pair of chromatids. The spindle networks disappear, and a new nuclear membrane forms. The chromosomes decondensation occurs and finally cytokinesis pinches the cell membrane in animal cells or the formation of the cell wall in plant cells, occurs, completing the creation of two daughter cells.

Meiosis II

Meiosis II is the second stage of the meiotic process. The overall process is similar to mitosis. The end result is production of four haploid cells. The four main steps of Meiosis II are: Prophase II, Metaphase II, Anaphase II, and Telophase II (see Fig 3).

Prophase II

In prophase II the nucleoli and nuclear envelope disappear. Centrioles move to opposite poles and arrange spindle fibers for the second meiotic division (see Fig 3).