How does Meiosis differ from Mitosis Students will know they are successful when they can……….. 1.Explain the reduction of chromosome number that occurs during meiosis 2.Recognize and summarize the stages of meiosis 3.Analyze the importance of meiosis in providing genetic variation

Chromosomes and Chromosome Number Chomosomes contain segments called genes that are used to control the production of proteins.

Homologous Chromosomes Each body cell has 46 Chromosomes (23 pairs), 23 from mom and 23 from dad. Pairs of Chromosomes are called Homologous.

Meiosis Meiosis: Is a type of cell division that reduces the number of chromosomes, that occurs in the reproductive cells of sexually reproducing organisms. It does this by going through 2 separate cell divisions, Meiosis 1 and Meiosis 2.

Comparing Mitosis to Meiosis 1 During Mitotic Metaphase each individual chromosome lines up along the metaphase plate During Meiosis Prophase 1, pairs of homologous chromosomes line up together, called synapsis.

Crossing Over and Recombination Crossing over: is a process during prophase 1 in which chromosomal segments are exchanged between a pair of homologous chromosomes, and increases the genetic variation of the gametes

The cell then Divides, and Meiosis 1 is finished, and ready for a second cell division called Meiosis 2.

Meiosis 2 During Meiosis 2 the cell once again goes through all the stages; prophase 2, metaphase 2, anaphase 2, telophase 2. But the chromosomes have not replicated again.

The result is 4 daughter cells each with their own unique genetic variation