1. Gamete Production

2. DNA Replicates (“S” stage)
1ST MEIOTIC INTERPHASE
Centrosomes
Nucleus
DNA
DNA Replicates (“S” stage)
Chromatin forms

3. MEIOSIS I

4. 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

5. Tetrads align in middle of cell
METAPHASE I
Tetrads align in middle of cell
Spindle fibers attach to centromeres

6. Crossing over creates recombinant chromosomes
ANAPHASE I
Crossing over creates recombinant chromosomes
Homologs separate and move apart
“Free” spindle fibers lengthen; cell elongates

7. Chromosomes reach centrosomes
TELOPHASE I
Chromosomes reach centrosomes

8. Nuclear membrane reforms Cell divides into two daughter cells
CYTOKINESIS I
Nuclear membrane reforms
Cell divides into two daughter cells

9. 2ND MEIOTIC INTERPHASE
CYTOKINESIS I

10. MEIOSIS II

11. PROPHASE II

12. METAPHASE II

13. ANAPHASE II

14. TELOPHASE II

15. CYTOKINESIS II

16. FOUR UNIQUE GAMETES