1. Cell Growth

2. Why cells divide:
the larger a cell become, the more demand the cell places on its DNA
the cell has more trouble moving enough nutrients and wastes across the cell membrane

3. Large Cells
DNA
the information that controls a cell’s function
nucleus
If a cell was to grow without limits, an ‘information crisis’ would occur.
Most wanted library book.

4. Exchanging Material
Cell Membrane: Food, Oxygen, and Water enter while waste products exit.
Surface Area
total area of cell membrane
rate of travel
Cell Volume: consumption & production rates
Car Doors vs. Bus Doors

5. Ratio of Surface Area to Volume
Cell needs small surface area to volume ratio.
With growth, cell volume cell increases more rapidly than surface area.
Large Cells: difficult to get sufficient oxygen and nutrient in and waste products out.
Small Town with a Two Lane Road

6. Division of the Cell
Cell Division: the process by which a cell divides into two daughter cells.
Before a cell divides, the DNA is copied.
Each cell receives its own set of the genetic library.

7. Chromosomes carry genetic information made of DNA
Each organism has a specific number of chromosomes.
Humans: 46; Fruit Flies: 8; Carrot: 18
Before cell division, each chromosome is replicated, or copied.

8. Structure Each chromosome consists of two sister chromatids.
The two sister chromatids are connected by a centromer.
When the cell divides, the sister chromatids separate from each other.
One chromatid goes to each of the two new cells.

10. Cell Cycle Cell Grows Prepares for Division
Divides into Two Daughter Cells
Cell Cycle Begins Again

12. Events of the Cell Cycle
Interphase: long period of time
G1 Phase: cell increases in size and synthesizes proteins and organelles
S Phase: chromosomes replicated and synthesis of DNA
G2 Phase: organelles and molecules are produced
M Phase: short period of time
Mitosis- division of cell nucleus
Cytokinesis-division of cytoplasm