1. 5.2 Mitosis and Cytokinesis
Chapter 5 Cell Growth and Division
Mr. Shilala
DAHS

2. KEY CONCEPT Cells divide during mitosis and cytokinesis.

3. DNA and Chromosomes
DNA is a double stranded molecule made of four subunits called nucleotides
A chromosome is one long continuous thread of DNA
Consists of numerous genes with regulatory information
Your cells have 46 chromosomes
If stretched out straight and laid end to end DNA in one cell would be about 10 feet long

4. Chromosomes condense at the start of mitosis.
DNA is loosely organized during interpahse
Looks like spaghetti
DNA wraps around proteins (histones) that condense (shrink) it.
DNA plus proteins is called chromatin
DNA double helix
DNA and histones
Chromatin
Supercoiled DNA

5. Telomeres protect DNA and do not include genes.
Chromatid
One half of a duplicated chromosome is a chromatid.
Sister chromatids (identical chromatids) are held together at the centromere.
Telomeres protect DNA and do not include genes.
Prevent chromosomes from accidentally attaching to each other
chromatid
telomere
centromere
Condensed, duplicated chromosome

6. Interphase prepares the cell to divide.
Mitosis and cytokinesis produce two genetically identical daughter cells.
Parent cell
centrioles
spindle fibers
centrosome
nucleus with
DNA
Interphase prepares the cell to divide.
During interphase, the DNA, or chromosomes, are duplicated.

7. Mitosis
Mitosis divides the cell’s nucleus into 2 genetically identical nuclei in four stages
Each has full set of DNA
IPMAT
Interphase
Not part of mitosis
Prophase
Metaphase
Anaphase
Telophase

8. Prophase DNA and Proteins condense into Chromosomes
Nuclear membrane breaks down, centrioles move to opposite poles and spindle fibers form

9. Metaphase Chromosomes line up in the middle of the cell.
Spindle fibers attach to each chromosome

10. Anaphase
Sister chromatids separate to opposite sides of the cell.

11. Telophase New nuclei form Chromosomes begin to uncoil
Spindle fibers fall apart.

12. Cytokinesis
Cytokinesis is the division of the cytoplasm into two cells
In animal cells, the membrane pinches closed.
In plant cells, a cell plate forms

13. Youtube Mitosis Video