1. Mitosis and Meiosis

2. Mitosis Cytokinesis Nuclear envelope start to disappear
Chromosomes become visible
Spindle fibers form from centrioles
Each chromosome contains 2 sister chromatids
DNA replicates
Cell grows
Chromosomes line up down middle of cell
Spindle fibers attach to centromeres
Nuclear envelope reforms
Cell dimples
Cell membrane/wall redevelops
Gets ready for cytokinesis
Chromosome split at centromere
Pulled to centrioles
Sister chromatids become chromsomes
Cytokinesis
Two daughter cells produced identical to one another

3. Meiosis 1 Prophase 1 Metaphase 1 Anaphase 1 Telophase 1
Homologous chromosomes pair up
Tetrads form
Crossing over can occur
Prophase 1
Metaphase 1
Homologous chromosomes line up down middle of cell
Spindle fibers attach to centromeres
Anaphase 1
Homologous chromosomes split
Telophase 1
Cell splits into 2 haploid cells

4. Meiosis 2 Telophase 2 Prophase 2 Metaphase 2 Anaphase 2
Two haploid cells
Prophase 2
Chromosomes line up down middle of cell
Spindle fibers attach to centromere
Metaphase 2
Sister chromatids split at centromere
Each become a chromosome
Anaphase 2
Telophase 2
4 daughter cells are produced each containing 23 chromosomes (haploid)
Carry identical genes but not identical traits

5. Comparison Mitosis Meiosis Results in 2 identical daughter cells
Each containing 46 chromosomes
Diploid
Happens over vast majority of body
Occurs so cell does not go into DNA overload
Allows cell to be efficient
Meiosis
Results in 4 cells with the same “basic” genetic information
Each cell contains 23 chromosomes
Haploid
Happens in reproductive organs
Has Meiosis 1 and 2
Meiosis 1 has homologous chromosomes and tetrads