1. Stages of Meiosis
Meiosis I

2. Interphase Same as mitosis DNA in chromatin
Centrioles
DNA
Nuclear Membrane
Same as mitosis
DNA in chromatin
Cells are growing and doing their normal cell jobs
DNA= 2n

3. Prophase I
DNA condenses into chromosomes and homologous chromosomes pair (homologous= carry same genes)
These chromosome pairs are called tetrads
Crossing over occurs in this step

4. Crossing Over
Parts of homologous chromosomes are exchanged

5. Metaphase I Like metaphase in mitosis
Chromosomes like up in the center of the cell
Nuclear membrane now gone

6. Stages of Meiosis
Meiosis II

7. Prophase II
The two newly formed cells continue into the next cycle of divisions known as Meiosis II.
No DNA replication between meiosis I and II
Centrioles and spindle fibers appear as the nuclear membrane breaks down and disappears.

8. Metaphase II Like all other metaphases
Chromosomes like up in the center of the cell
Nuclear membrane now gone

9. Anaphase II Same as anaphase in mitosis
Centromeres detach from each other
Chromatids are pulled to opposite ends of the cells by microtubules

10. Telophase II and Cytokinesis
Nuclear membrane reforms
Cytoplasm is divided between new cells
DNA goes back to chromatin

11. Human Males vs. Females
In human males, all four cells become viable haploid gametes
In females, only one of the cells will develop into a egg, rest are polar bodies

12. Sibling Variation
Using your understanding of meiosis, explain why brothers and sisters from the same parents have similarities and differences in appearance.
The variety of genetic inheritance due to crossing over and random gene selection in meiosis can account for differences and similarities between siblings.