1. Cell Cycle

2. How do cells make more cells?
They grow and divide!
The process of cells growing and dividing is known as the cell cycle.
Why do cells need to do this? Hmmm…
Cell cycle – cells growing and dividing

3. Stages of Cell Cycle There are 3 stages Interphase Mitosis Cytokinesis
All of the cell cycle occurs in the nucleus!

4. Parts to know…
We need to understand some parts of the cell before we begin looking at each step.
Centrioles
Chromatin
DNA
Chromosomes

5. Centrioles Come in pairs Look like a macaroni noodle or barreled shape
Found in the cytoplasm
Like to hang out at the north pole of the cell
They are orange here

6. Centrioles

7. Chromatin
Definition: Mass of genetic material composed of DNA and proteins.
Chromatin is located in the nucleus of a cell.
During mitosis (2nd stage), chromatin condenses to form chromosomes.

8. DNA in Chromatin I mentioned that chromatin is made of DNA.
What is DNA?
DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms.
Most DNA is located in the cell nucleus.
So, chromatin is composed of DNA and chromatin condenses to form chromosomes.

9. Chromosomes
Once again chromatin is composed of DNA and chromatin condenses to form chromosomes.
What are chromosomes?
It is a single piece of coiled DNA

10. Chromosomes

11. Structure of Chromosome
The centromere acts like a button. It keeps the 2 chromatids together making the double rod “X” structure.

12. Stage 1- Interphase Interphase: Growth Phase
This is the period where the cell grows and prepares for division.  It is divided into three parts:
G1: The cell grows
S: The cell replicates its chromosomes (DNA).
G2: The cell replicates its organelles and prepares for division.

13. Stage 1- Interphase
During interphase, the chromosomes are not visible.  They are uncoiled.  When the DNA is in this uncoiled form it’s called chromatin. 
The reason it’s uncoiled is this allows it to be copied more easily.

14. Stage 1- Interphase
The cell spends most of its life in the interphase stage.

15. Visit Stage 1- Interphase
/active_art/cell_cycle/index.html
Now the cell is ready to divide. Next stage…

16. Stage 2 - Mitosis Mitosis: Division of the Nucleus
This is divided into four steps:
Prophase
Metaphase
Anaphase
Telophase

17. Stage 2 Mitosis…Step 1 Prophase
Chromatin condenses to form chromosomes
Centrioles move to opposite ends of cell
Nuclear envelope starts to break down.

18. Visit Mitosis… Step 1 Prophase
/active_art/cell_cycle/index.html
Time to move to the next step of mitosis…

19. Stage 2 Mitosis…Step 2 Metaphase
The chromosomes line up in the MIDDLE of the cell.
The centrioles are at north & south poles.
MMMMetaphase……..MMMMiddle

20. Visit Mitosis… Step 2 Metaphase
/active_art/cell_cycle/index.html
Time to move to the next step of mitosis…

21. Stage 2 Mitosis…Step 3 Anaphase
Remember the centromeres
that act like a button and hold
the chromosomes together?
Well, not anymore. The centromeres break.
Thus, the chromosome is seperated and becomes two chromatids again.
Each chromataid moves
to opposite ends of cell.
AAAnaphase…AAAway

22. Visit Mitosis… Step 3 Anaphase
/active_art/cell_cycle/index.html
Time to move to the last step of mitosis…

23. Stage 2 Mitosis…Step 4 Telophase
A new nuclear envelope has formed around each region of chromosomes
TTTwo Nucleus(Nuclei)…TTTelophase

24. Stage 2 Mitosis….Step 4 Telophase
/active_art/cell_cycle/index.html
The last step of mitosis.

25. Stage 3 - Cytokinesis cyto- (cell) and kinesis (motion, movement)
Cytokinesis is the process in which the cytoplasm of a single eukaryotic cell is divided to form two daughter cells.

26. Stage 3 - Cytokinesis
/active_art/cell_cycle/index.html
A look at the last stage of the cell cycle.