Meiosis Division of Gametes

Somatic Cells vs. Gametes Somatic cells-body cells, are diploid (2n) and have 2 sets of chromosomes (one from each parent) Gametes-sex cells (sperm and eggs), are haploid (n) and have 1 set of chromosomes

How do we get haploid gametes? Meiosis! Needed so that when gametes join together in fertilization, the zygote the create is diploid Results in 4 NON-identical haploid daughter cells

Homologous Chromosomes Chromosomes THAT HAVE THE GENES FOR THE SAME TRAIT ONE FROM EACH PARENT Form a tetrad

Meiosis Meiosis 1: First Division of Meiosis prophase I: similar to prophase in mitosis metaphase I: the homologous chromosomes line up at the equator anaphase I: the homologous chromosomes separate to opposite poles telophase I: similar to telophase in mitosis (results in 2 haploid nuclei)

Meiosis Meiosis II: the 2 daughter cells go through a second division, resulting in 4 haploid, non-identical daughter cells total.

Crossing over During meiosis I, when homologous chromosomes form a tetrad, crossing over can occur. Alleles are exchanged between homologous chromosomes