1. KEY CONCEPT Cells divide during mitosis and cytokinesis.

2. Chromosomes condense at the start of mitosis.
DNA wraps around proteins (histones) that condense it.
DNA double helix
DNA and histones
Chromatin
Supercoiled DNA

3. DNA plus proteins is called chromatin.
chromatid
telomere
centromere
One half of a duplicated (replicated) chromosome is a chromatid.
Sister chromatids are held together at the centromere.
Telomeres protect DNA and do not include genes.
Condensed, duplicated chromosome

4. Mitosis and cytokinesis produce two genetically identical daughter cells.
Parent cell
centrioles
spindle fibers
centrosome
nucleus with
DNA
Interphase (remember 3 stages – G1, S and G2) During S of interphase, the DNA is copied (replicated).

5. Mitosis divides the cell’s chromosomes in four phases.
1. Prophase, chromosomes condense and spindle fibers form. They “attach”.

6. 2. Metaphase - chromosomes line up in the middle of the cell
2. Metaphase - chromosomes line up in the middle of the cell. (no nucleus)

7. 3. Anaphase, sister chromatids separate to opposite sides of the cell.

8. 4. Telophase, the new nuclei form and chromosomes begin to uncoil.

9. Cytokinesis differs in animal and plant cells.
In animal cells, the membrane pinches closed. (outside in)
In plant cells, a cell plate forms (inside out)