Meiosis Notes

Meiosis – What is it? a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores. ensures that offspring are genetically different from their parents.

Significance of Meiosis results in gametes (sex cells)! Major source of variation, which leads to Natural Selection

Meiosis Starts diploid and ends haploid through 8 steps

Stages of meiosis

Meiosis I Prophase 1 – The chromosomes condense, and the nuclear envelope breaks down. Crossing over occurs. Metaphase 1 – Pairs of homologous chromosomes move to the equator of the cell. Anaphase 1 – Homologous chromosomes move to the opposite poles of the cell. Telophase 1 – Chromosomes gather at the poles of the cells.

Meiosis II Prophase 2 – A new spindle forms around the chromosomes. Metaphase 2 – Chromosomes line up at the equator. Anaphase 2 – Centromeres divides. Chromatids move to the opposite poles of the cells. Telophase 2 – A nuclear envelope forms around each set of chromosomes.

Crossing Over in The exchange of genes between homologous chromosomes, resulting in a mixture of parental characteristics in offspring Results in new gene combinations This is why you have some genes from your mom and some from your dad!

Life Cycle including Mitosis and Meiosis