The Meiosis Animation This animation illustrates the process of meiosis, where germ cells divide to make haploid gametes such as the egg and sperm. The chromosomes have been color coded for each parent. For example, the orange chromosomes were inherited from your father, while the green chromosomes were inherited from your mother. Certain events are not illustrated in this animation due to the limits of PowerPoint, such as chromosome crossing over.

Here is a diploid cell. 46 strands of chromatin. Orange = from father; Green = from mother During the S stage of interphase, the chromatin strands are duplicated. There are now 92 strands of chromatin.

During prophase I, the nucleus dissolves

During prophase I, the chromatin coils into chromosomes Notice there are two of every chromosome number…one you inherited from your mother and one from your father. 1 5 12 9 8 22 13 15 6 11 11 17 18 19 13 14 18 2 6 1 7 21 9 17 15 10 4 23 16 7 22 10 3 19 3 21 16 4 5 20 14 2 20 23 8 12

This creates 23 tetrads. Tetrads have 4 chromatids each. During prophase I, synapsis occurs. Spindle fibers pull the pairing of homologous chromosomes to each other. 1 5 12 9 8 22 13 15 6 11 11 17 18 19 13 14 18 2 6 1 7 21 9 17 15 10 4 23 16 7 22 10 3 19 3 21 16 4 5 20 14 2 20 23 8 12 This creates 23 tetrads. Tetrads have 4 chromatids each.

During metaphase I, the spindle fibers pull the tetrads to the cell equator 8 8 15 15 11 11 17 17 18 18 19 19 13 13 6 1 1 6 7 7 9 9 10 10 16 16 22 22 3 3 21 21 4 4 5 5 14 14 2 2 20 20 23 23 12 12

During anaphase I, the homologous chromosomes are separated. 8 8 15 15 1 1 11 11 During anaphase I, the homologous chromosomes are separated. 18 18 After telophase I, cytokinesis divides the cell into two 13 13 19 19 10 10 17 17 6 6 7 7 16 16 22 22 3 3 5 5 14 14 9 9 4 4 21 21 20 20 23 23 2 2 12 12

During anaphase II, the sister chromatids are pulled apart After telophase II, cytokinesis divides the cytoplasm again Each cell now only has ½ the genetic material that it started with…haploid cells!