1. Meiosis

2. Meiosis
Review:
A type of cell division in which one 2n cell becomes four 1n cells
Built into the process is genetic variability
In complex organisms, each of the final cells is practically unique!

3. Independent Assortment
Homologous chromosomes:
Chromosomes that carry information for the same genes
Will be the same shape, size and have the same location of the centromere
They are NOT exact copies of each other
Example: If chromosome 1 has the loci for the eye color gene, chromosome 1a could have the brown gene while chromosome 1b could have the blue gene

4. Independent Assortment
Homologous chromosomes:
In humans, we have 23 pairs of homologous chromosomes

5. Independent Assortment
Homologous chromosomes:
During meiosis 1, homologous chromosomes:

6. Independent Assortment
Homologous chromosomes:

7. Independent Assortment
Homologous chromosomes:
For an organism with 4 chromosomes (2 pairs) there are 4 possible gamete cells that can be created (2# of pairs)
For humans with 46 chromosomes (23 pairs) there are 223 possible gametes that can be created or 8,388,608 possibilities

8. Recombination
Crossing Over:

9. Recombination
Crossing Over:
Random shuffling

10. Gametogenesis
Formation of sex cells (gametes) that occurs during meiosis
In most animals, this process differs between males and females
Spermatogenesis:
Oogenesis:

11. Gametogenesis