meiosis

1. Gamete Production meiosis

2. Tetrad Kinetocore Centromere Sister Chromatid Need-to-know Vocabulary Replicated Chromosome Homologous Chromosomes

3. Like in the Interphase of mitosis, meiosis starts with the splitting of the centriole and the duplication of DNA Interphase

4. Now, the Chromatin coils into chromosomes and pair up with their homologous match. The centrioles move to the poles as the nuclear membrane and the nucleolus disappear Prophase 1

5. The homologous pairs move to the equator, and the centrioles attach spindle fibers to the kinetocore of the nearest chromosome. Metaphase 1

6. Before metaphase I, homologous chromosomes will exchange pieces of DNA which is known as “crossing over” This process officially happens while in Prophase I. Metaphase 1

7. The polar fibers retract, separating the homologous pairs. Anaphase 1

8. The cell splits in two, each with one centriole and one set of replicated chromosomes. The spindle fibers will disappear. Telophase 1

9. Note: Many illustrations skip Interphase 2, because it’s considered unnecessary, and usually jump straight to Prophase 2 with the understanding that centrioles replicated. Telophase 1

10. Prophase 2 The centrioles duplicate themselves again and move to the equator

11. The replicated chromo-somes move to the equator. The centrioles throw out their spindle fibers to attach to the kinetochores. Metaphase 2

12. The polar fibers retract and separate the sister chromatids. Anaphase 2

13. Telophase 2 The spindle fibers disappear The chromosomes gather as the nuclear membrane and the nucleolus re-appear

14. Telophase 2 Both cells divide, creating 4 separate haploid cells

15. Cytokinesis

16. Cytokinesis Finally, the chromosomes uncoil into chromatin, completing meiosis