1. Watch the slideshow to see the slides clearly.

2. Section 3: Cell Division
What events take place during the three states of the cell cycle?
How does the structure of DNA help account for the way in which DNA copies itself?

3. The Cell Cycle
Cell Cycle: The regular sequence of growth and division that cells undergo.
Made up of 3 stages:
Stage 1: Interphase
Stage 2: Mitosis
Stage 3: Cytokinesis

4. Interphase Cells spend most of their time in this phase.
During Interphase, the following 5 events will occur:
The cell will perform its “normal” functions and duties.
The cell will grow to about twice it's original size.
The cell's organelles will make copies of themselves and double in quantity.
The cell's DNA will make a copy of itself right before Mitosis begins.
Once the DNA is copied, the cell will make structures that it will use to help divide itself.

5. Mitosis
During mitosis, the cell’s nucleus divides into two new nuclei. One copy of the DNA is distributed into each of the two daughter cells.

6. Mitosis
Four stages in Mitosis:
Prophase
Metaphase
Anaphase
Telophase

7. Mitosis: Prophase
“Chromatin” winds up into a condensed shape called “chromatid”.
Chromatin: unwound DNA
Chromatid: wound DNA

8. Mitosis: Prophase
The cell gets ready for the “Tug of War” activity that occurs in Mitosis.

9. Mitosis: Prophase
The cell gets ready for the “Tug of War” activity that occurs in Mitosis.
The pair of centrioles move to opposite sides of the nucleus.
Spindle fibers (the “ropes”) form between the centrioles.
The nuclear envelope that surrounds the nucleus breaks down.

10. Mitosis: Metaphase
The chromatids line up on the equator of the cell.

11. Mitosis: Anaphase
The chromatids separate and move to opposite sides of the cell.
The cell starts to stretch apart as it gets ready for Cytokinesis.

12. Mitosis: Telophase
Chromatids unwind and return to their string- like chromatin shape.
2 new nuclear envelopes form to make 2 new nuclei.

13. Cytokinesis
Must finish after Mitosis or else the cell will split into 2 cells before the DNA is evenly divided.
The 2 new cells are called “daughter cells”.
Each daughter cell is identical to the original parent cell.

14. The Cell Cycle