• Cheek cells

Gametic Cell Division - basic principle

Lily anther with pollen grains Cells undergoing meiosis to form haploid pollen grains Four pollen sacs of an anther

Gametic division plaque Anaphase II - Chromosomes split and chromatids move towards the opposite poles Anaphase II - Chromosomes split and chromatids move towards the opposite poles Anaphase II - Chromosomes split and chromatids move towards the opposite poles Anaphase II - Chromosomes split and chromatids move towards the opposite poles Anaphase I - Homologous chromosomes separate and move towards opposite pairs Anaphase I - Homologous chromosomes separate and move towards opposite pairs Telophase II - Separated chromatids now referred to as chromosomes reach the opposite poles, four haploid nuclei are formed Telophase II - Separated chromatids now referred to as chromosomes reach the opposite poles, four haploid nuclei are formed Telophase II - Separated chromatids now referred to as chromosomes reach the opposite poles, four haploid nuclei are formed Telophase II - Separated chromatids now referred to as chromosomes reach the opposite poles, four haploid nuclei are formed Metaphase II - Individual chromosomes move to the center of the spindle Metaphase II - Individual chromosomes move to the center of the spindle Telophase I / Prophase II - Chromosomes reach the opposite poles; two haplois nuclei are formed; each chromosome is composed of two chromatids joined at centromere Telophase I / Prophase II - Chromosomes reach the opposite poles; two haplois nuclei are formed; each chromosome is composed of two chromatids joined at centromere Metaphase I - Homologous chromosome pairs move to the equator of the spindle to form a metaphase plate Prophase I - Chromosomes form pairs and exchange genes (crossing over and chaismata) Prophase I - Chromatin condenses to form chromosomes

Meiosis 1 Two cells separate; each with a haploid nucleus Cell wall (cell plate) separates the two haploid nuclei Chromosomes reach the opposite poles and form two haploid nuclei Homologous chromosomes separate and move towards the opposite poles of the spindle Homologous chromosomes move to the center of the spindle - metaphase plate Chromatin condenses to form chromosomes; homologous chromosomes pair and exchange genes (crossing over, chiastmata) Cytokinesis - cell plate Spindle fibers New haploid nucleus New haploid nucleus Homologous chromosomes moving towards opposite poles of the spindle Metaphase plate Chromatin condenses to form chromosomes

Meiosis 2 Chromosomes Metaphase plates Four haploid cells are formed Four hapolid nuclei Individual chromosomes line up along the center of the spindle in both the cells Chromosmes condense