5 2 Mitosis and Cytokinesis KEY CONCEPT Cells

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5. 2 Mitosis and Cytokinesis KEY CONCEPT Cells divide during mitosis & cytokinesis.

5. 2 Mitosis and Cytokinesis KEY CONCEPT Cells divide during mitosis & cytokinesis.

Phenomenon: Scientists grow an ear on the back of a mouse. https: //www. youtube.

Phenomenon: Scientists grow an ear on the back of a mouse. https: //www. youtube. com/watch? v=7 Ql. WBn. L 0 zj. U • Why would we grow an ear on a mouse? ?

5. 2 Mitosis and Cytokinesis Chromosome Structure • 1 long thread of DNA •

5. 2 Mitosis and Cytokinesis Chromosome Structure • 1 long thread of DNA • DNA wraps around proteins (histones) that condense it. • DNA + Histones form chromatin • Chromosomes condense tightly for mitosis DNA double helix DNA and histones Chromatin Supercoiled DNA

5. 2 Mitosis and Cytokinesis • DNA plus proteins is called chromatin. • One

5. 2 Mitosis and Cytokinesis • DNA plus proteins is called chromatin. • One half of a duplicated chromosome is a chromatid. • Sister chromatids are held together at the centromere. • Telomeres protect DNA and do not include genes. chromatid telomere centromere telomere Condensed, duplicated chromosome

5. 2 Mitosis and Cytokinesis Mitosis and cytokinesis produce two genetically identical daughter cells.

5. 2 Mitosis and Cytokinesis Mitosis and cytokinesis produce two genetically identical daughter cells. Parent cell • 1. Interphase prepares the cell to divide. • Copies DNA • Cell grows • Organelles are duplicated nucleus with DNA centrioles spindle fibers centrosome

5. 2 Mitosis and Cytokinesis • Mitosis divides the cell’s nucleus in four phases.

5. 2 Mitosis and Cytokinesis • Mitosis divides the cell’s nucleus in four phases. 2. Prophase: chromosomes condense nuclear envelope breaks down Spindle fibers form.

5. 2 Mitosis and Cytokinesis – 3. Metaphase- spindle fibers help chromosomes line up

5. 2 Mitosis and Cytokinesis – 3. Metaphase- spindle fibers help chromosomes line up in the middle of the cell

5. 2 Mitosis and Cytokinesis 4. Anaphase, sister chromatids separate to opposite sides of

5. 2 Mitosis and Cytokinesis 4. Anaphase, sister chromatids separate to opposite sides of the cell.

5. 2 Mitosis and Cytokinesis 5. Telophase: Nuclear membrane forms around chromosomes begin to

5. 2 Mitosis and Cytokinesis 5. Telophase: Nuclear membrane forms around chromosomes begin to uncoil Spindle fibers fall apart

5. 2 Mitosis and Cytokinesis differs in animal and plant cells. • Animal cells

5. 2 Mitosis and Cytokinesis differs in animal and plant cells. • Animal cells - the membrane pinches closed. • Plant cells - a cell plate forms.