1. produces “gametes”: sex cells Male: sperm X and Y Female: eggs

2.  Meiosis: divided into 2 stages:  Meiosis I  Meiosis II

3.  PROPHASE I: spindle fibers appear homologous chromosomes pair **this happens only in meiosis!

4.  Synapsis: the pairing of homologous chromosomes  Tetrad: each pair of homologous chromosomes  Aligned so that genes line up

5.  alignment

6.  Crossing-over occurs:  Chromatids twist around each other  Portions of chromatids break off and attach to the adjacent chromosome  Creates “genetic recombination”: new mix of genetic material

7.  Tetrads line up along equator of cell  Spindle fibers are attached to centromere

8.  Each homologous chromosome moves to the opposite pole  “INDEPENDENT ASSORTMENT”: random separation of chromosomes

9.  Chromosomes reach opposite ends  Cytokinesis I begins  These cells are HAPLOID! But ….. Each cell contain 2 copies (chromatids)

10.  Some organsism, interphase first occurs  In other organisms, you go straight from telophase I to prophase II

11.  Spindle fibers form

12.  Chromosomes line up along the midline  Each chromatid faces the opposite poles

13.  Chromatids separate and move toward opposite poles

14.  Nuclear memb forms around the chromosome in the 4 new cells  Cytokinesis II occurs  Each cell is haploid

16.  Spermatogenesis: the production of sperm  Occurs in the testes  4 sperm created  Oogenesis: production of “ova” or eggs  3 polar bodies made and 1 egg