1. What are the 3 main stages of the cell cycle?
Please write these two questions on the handout I gave you at the door.
What are the 3 main stages of the cell cycle?
What are the four stages of mitosis and explain what occurs in each?

2. KEY CONCEPT Cells have distinct phases of growth, reproduction, and normal functions.

3. The cell cycle has four main stages.
The cell cycle is a regular pattern of growth, DNA replication, and cell division.

4. The main stages of the cell cycle are gap 1, synthesis, gap 2, and mitosis.
Gap 1 (G1): cell growth and normal functions
DNA synthesis (S): copies DNA
Gap 2 (G2): additional growth
Mitosis (M): includes division of the cell nucleus (mitosis) and division of the cell cytoplasm (cytokinesis)
Mitosis occurs only if the cell is large enough and the DNA undamaged.

5. Cells divide at different rates.
The rate of cell division varies with the need for those types of cells.
Some cells are unlikely to divide (G0).

6. Cell size is limited.
If cells were too small, they could not contain all the organelles and molecules necessary for life.
If cells were too large, they could not move enough materials across the membrane surface.
To maintain a suitable size, cell growth and division must be coordinated.

7. Surface area must allow for adequate exchange of materials.
Cell growth is coordinated with division.
Cells that must be large have unique shapes.