1. KEY CONCEPT Cells divide during mitosis & cytokinesis.

2. Phenomenon: Scientists grow an ear on the back of a mouse.
Why would we grow an ear on a mouse??

3. 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

4. DNA plus proteins is called chromatin.
chromatid
telomere
centromere
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.
Condensed, duplicated chromosome
Contains hidden text (telomeres) under sister chromatids

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

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

7. 3. Metaphase- spindle fibers help chromosomes line up in the middle of the cell

8. 4. Anaphase, sister chromatids separate to opposite sides of the cell.

9. 5. Telophase: Nuclear membrane forms around chromosomes
chromosomes begin to uncoil
Spindle fibers fall apart

10. Animal cells - the membrane pinches closed.
Cytokinesis differs in animal and plant cells.
Animal cells - the membrane pinches closed.
Plant cells - a cell plate forms.