1. Warm Up
Draw chromatin, chromatid(s), and chromosome(s) and describe them. Frayer model Quiz, answer sheets, amoeba sister video and answer sheet

2. Warm Up
Chromosome Review:

3. Meiosis

4. In meiosis gametes or sex cells (egg and sperm) are made .
Meiosis involves 2 divisions
1. Meiosis I
2. Meiosis II
During meiosis I homologous pairs of chromosomes separate.
This reduces the number of chromosomes from 2n to n.
This means that each egg and sperm cell has n chromosomes.

5. Meiosis I

6. Prophase I
Homologous chromosomes will swap genetic material in a process known as crossing- over. This gives genetic variation (genetic recombination)

7. Metaphase I
Microtubules grow from the centrioles and attach to the centromeres. The homologous pairs of chromosomes line up along the cell equator.

8. Anaphase I
Homologous chromosomes separate. NOTE that chromatids are still attatched.

9. Telophase I
At the end the cells are haploid- this means that they have ½ of the normal number of chromosomes.

10. Meiosis II
Is identical to mitosis from this point on but with 2 dividing cells instead of one.

11. Turn & Talk

12. Meiosis I Summary

13. Prophase II
The nuclear envelope breaks down and the spindle fibers begin to form in each daughter cell from meiosis I. The centrioles also start to separate.

14. Metaphase II
The spindle fibers line up the sister chromatids of each chromosome along the equator of the cell

15. Anaphase II
The sister chromatids separate and move to the opposite poles.

16. Telophase II & Cytokinesis
The spindle fibers break down
A new nuclear membrane forms
The cytoplasm of each cell divides
4 haploid cells result
Each cell has a unique combination of chromosomes.

18. Summarize
At the bottom of your notes page, write 2 to 3 sentences comparing mitosis and meiosis. How are they similar? How are they different?