MeiosisMeiosis

MeiosisMeiosisA type of cell division that

produces four cells each with half the number of chromosomes as the parents

Homologous Chromosomes: Two pairs of chromosomes that carry the same genetic material

Haploid and DiploidHaploid and Diploid

Haploid◦A cell with a single set of chromosomes

◦Shown as n◦A human has 23 chromosomes

Diploid◦A cell with two sets of chromosomes

◦Shown as 2n◦A human has 46 chromosomes

as 2n

MeiosisMeiosis

Produces 4 genetically different haploid cells

Has two division stages◦Meiosis I◦Meiosis II

MeiosisMeiosis

Meiosis IMeiosis IProphase I

◦Creation of homologous chromosomes

◦Tetrads are formed◦Homologous chromosomes crossover

Meiosis IMeiosis IMetaphase I

◦Tetrads line upAnaphase I

◦Homologous chromosomes separate

Telophase I and Cytokinesis◦Cells separate with

homologous chromosomes

Meiosis IMeiosis I

Meiosis IIMeiosis IIProphase IIMetaphase II

◦Sister Chromatids Line upAnaphase II

◦Sister Chromatids separate Telophase II and Cytokinesis

◦Cells split and create haploid genetically different daughter cells

MeiosisMeiosisCreates four genetically different daughter cells

Crossing over creates genetic variation

Only sex cells go through meiosis

Gamete: A sex cell created by meiosis- Sperm or Egg

Mitosis VS. Mitosis VS. MeiosisMeiosisMitosis

◦Creates 2 identical daughter cells

◦Does not exchange or change genetics

◦One stage◦Diploid

Meiosis◦Creates 4 genetically different daughter cells

◦Exchanges or changes genetics through crossing over

◦Two stages◦Haploid