Mitosis Cytokinesis Chromosomes Eukaryotic Chromatids DNA must be

Mitosis & Cytokinesis

Chromosomes & Eukaryotic Chromatids DNA must be tightly coiled to fit inside a cell (each of your cells contains six feet of it!) Chromatin is formed when DNA is wrapped around protein spools Chromosomes form when chromatin is supercoiled Chromosome s Chromatin

Chromosomes & Chromatids Before S phase, each chromosome is made of one DNA molecule called a chromatid After S phase (DNA is copied), each chromosome consists of two identical DNA molecules called sister chromatids Numb chrom er of does osomes n they’r ’t change, e just the s twice ize!

PHASES OF MITOSIS (PMAT) Prophase Metaphase Anaphase Telophase Mitosis is a part of cell division where the nucleus divides

PMAT “Prepare” Mitosis consists of four phases. The first is… 1. Prophase • Chromatin condenses into chromosomes • Nucleolus and nuclear membrane disappear • Centrioles move towards poles of cell and start to form spindle fibers Interphas e Prophase

PMAT

2. Metaphase PMAT “Middle” • Chromosomes align at the equator of the cell • Spindle fibers attach to the centromere of each chromosome Metapha se

3. Anaphase PMAT “Apart/ Away” • Spindle fibers pull centromeres apart • Sister chromatids are pulled towards poles of cell Anaphase

4. Telophase PMAT “Two” • Chromatids reach the poles • Nuclear membranes reform around new nuclei Telophase

CYTOKINESIS Cytokinesis is the part of cell division where the cytoplasm and cell membrane divide

Cytokinesis It pinches the cell in two, separating membrane, cytoplasm, and nuclei