MEIOSIS Gamete Formation

Process of nuclear division that reduces the number of Meiosis= Process of nuclear division that reduces the number of chromosomes in new cells to HALF the number in the original cell. Click here to see fertilization and chromosome numbers

Female Gamete=Egg Cell Meiosis results in. . . . Sex Cells Female Gamete=Egg Cell Male Gamete = Sperm Cell

Cells undergo all phases of interphase Then they enter Meiosis which involves 2 distinct cell divisions

Prophase I (crossing over) Metaphase I Stages of Meiosis Meiosis I Prophase I (crossing over) Metaphase I Anaphase I (homologous chromosomes separate) Telophase I and cytokinesis

Portions of chromatids break off and attach to adjacent Crossing Over Portions of chromatids break off and attach to adjacent chromatids on the homologous chromosome occurs during prophase I

Meiosis I Interphase Prophase I Metaphase I Anaphase I Telophase I Cytokinesis Images from: http://www.phschool.com/science/biology_place/biocoach/meiosis/teloi.html

Anaphase II (sister chromatids separate) Stages of Meiosis Meiosis II Prophase II Metaphase II Anaphase II (sister chromatids separate) Telophase II and cytokinesis (4 haploid cells result)

Meiosis II Coming from Meiosis I Prophase II Metaphase II Telophase II Anaphase II Cytokinesis Images from: http://www.phschool.com/science/biology_place/biocoach/meiosis/teloi.html

Meiosis 1 = Separates Homologous Chromosomes Meiosis 2 = Separates Sister Chromatids Image from: http://wise.berkeley.edu/student/topFrame.php?projectID=23132

four unique daughter cells are produced Summary At the end of meiosis II, four unique daughter cells are produced (4 haploid cells) * *