1. Nuclear division of sex cells
Meiosis
Nuclear division of sex cells

2. Meiosis Two divisions of a single nucleus occur
Produces gametes (sex cells)
Eggs
Sperm
Fertilization- joining of sex cells
Producing a zygote

3. Meiosis
Because meiosis joins 2 cells, unlike mitosis that occurs in 1 cell
Each sex cell should only contain 1 copy of each chromosome (23 total chromosomes….no pairs)
So this is why nuclear division occurs twice
This results in Meiosis 1 and Meiosis 2

4. Meiosis Produces gametes (sex cells) Interphase
Time between cell divisions
3 phases
G1 phase- growth
S phase- DNA replicate creating a duplicate chromosome
G2 phase- prepare to divide

5. Meiosis Meiosis- Prophase I Pairs of homologous chromosomes
Remember each chromosome

6. Meiosis Meiosis- Metaphase I
Homologous chromosome pair line up in the center of the nucleus

7. Meiosis Meiosis- Anaphase I
Chromosomes separate and move to the opposite ends of the nucleus

8. Meiosis Meiosis- Telophase I and Cytokinesis I
Chromosomes reach opposite sides of the cell
New nuclear membrane forms
The new nucleus each contains a chromosome with 2 chromatids
The cell divides

9. Meiosis Meiosis- Prophase II No replication takes place
Each cell contains one chromosome from the homologous pair

10. Meiosis Meiosis- Metaphase II
Chromosomes line up in the middle of the cell

11. Meiosis Meiosis- Anaphase II Chromatids separate
Move towards the poles (opposite sides of the nucleus)

12. Meiosis Meiosis-Telophase II and Cytokinesis II
Nuclear membrane forms around the chromosome
4 new cells are formed each with half the number of chromosomes
Example humans 23 chromosomes

14. Meiosis End Products 4 Daughter cells 23 chromosomes each
Create either an egg or sperm cell