Gamete Production
DNA Replicates (“S” stage) 1ST MEIOTIC INTERPHASE Centrosomes Nucleus DNA DNA Replicates (“S” stage) Chromatin forms
MEIOSIS I
DNA condenses into chromosomes PROPHASE I GERM CELL DNA condenses into chromosomes PROPHASE I Homologous chromosomes pair up to form a tetrad. Spindle fibers form Crossing over may occur Centrosomes move apart Nuclear envelope breaks down
Tetrads align in middle of cell METAPHASE I Tetrads align in middle of cell Spindle fibers attach to centromeres
Crossing over creates recombinant chromosomes ANAPHASE I Crossing over creates recombinant chromosomes Homologs separate and move apart “Free” spindle fibers lengthen; cell elongates
Chromosomes reach centrosomes TELOPHASE I Chromosomes reach centrosomes
Nuclear membrane reforms Cell divides into two daughter cells CYTOKINESIS I Nuclear membrane reforms Cell divides into two daughter cells
2ND MEIOTIC INTERPHASE CYTOKINESIS I
MEIOSIS II
PROPHASE II
METAPHASE II
ANAPHASE II
TELOPHASE II
CYTOKINESIS II
FOUR UNIQUE GAMETES