1. Meiosis
Why We Are Who We Are

2. Meiosis Takes place in the Gametes (sex cells) of an organism
People have a Chromosome count of 46
When an egg joins a sperm the count must stay at 46 to remain human
So, the egg can only have 23 chromosomes, and the sperm can only have 23 chromosomes
How does this happen?

3. + = Sperm (23) + Egg (23) = Fertilized Cell (46)
During Meiosis gamete (sex) cells undergo a “double division” reducing the chromosomal count to 23. + =
Sperm (23) + Egg (23) = Fertilized Cell (46)

4. Original Gamete Metaphase Anaphase Telophase Cytokinesis
2 Daughter Cells Metaphase 2 Anaphase 2 Telophase 2 Cytokinesis – 4 Gametes

5. At the end of Meiosis the individual Gamete cell has divided from one cell to four.

6. Meiosis ensures that all living organisms will maintain both Genetic Diversity and Genetic Integrity

7. 4 2 2 46 23 SUPER SLUETH! How many divisions occur in Meiosis?
How many cells result from the end of Meiosis one?
How many cells are produced at the end of Meiosis two?
How do sex cells differ from the parent cell?
Meiosis begins with ______ chromosomes.
Meiosis ends with ____ chromosomes. 4 2 2 46 23
½ the chromosomes

8. 4. Ending # of Chromosomes
Mitosis
Meiosis
1. What type of cells?
2. Starting # of Cells
3. Ending # of Cells
4. Ending # of Chromosomes