1. Chapter 10
Cell Growth & Division

2. 10-1 Cell Growth
Question: Are cells in a mouse and a whale the same size??
INTEREST GRABBER (10-1)
The larger a cell becomes, the more demands the cell places on its DNA. In addition, the cell has more trouble moving enough nutrients and wastes across the membrane

3. Limits to Cell Growth DNA “overload” Surface area to volume ratio
DNA is unable to meet needs of a large cell
Surface area to volume ratio
Volume increases more rapidly than surface area
Exchanging Materials
The rate at which oxygen, food, & waste are used up depends on the cell’s volume
The rate at which oxygen, food, & waste diffuse across the membrane depends on the cell’s surface area

5. Division of the Cell
Before cells become too big, they divide forming two “daughter” cells.
The process of division is called cell division.

6. 10-2 Cell Division
In eukaryotic cells, genetic information is passed on from one generation to the next by chromosomes.
Chromosomes are made of DNA
Human cells have 46 chromosomes

7. Purposes of Mitosis Reproduction of unicellular organisms
Types of asexual reproduction
Growth / repair in multicellular organisms

9. The Cell Cycle
The cell cycle is a series of event that cells go through as they grow and divide.
During the cell cycle, a cell …
Grows
Prepares for division
Divides to form 2 daughter cells
Each of which begin the cell cycle again!!

10. Events of the Cell Cycle
Interphase
Has three phases: G1, S, and G2
Cell Grows
Chromosomes replicate

11. MITOSIS Prophase Longest Phase 50 – 60% of the total time of Mitosis
Spindle Fibers Form
Nuclear Envelope Disappears
Chromosomes Coil up more tightly

12. 2) Metaphase
Chromosomes line up across the center of the cell

13. 3) Anaphase
Sister chromatids separate and move to opposite ends of the cell

14. 4) Telophase Chromosomes uncoil Nuclear Envelope reappears
Spindle fibers disappear

15. Cytokinesis
Splitting of the cytoplasm into two cells!

16. Mitosis video (15 minutes)

17. 10-3 Regulating the Cell Cycle
READ pages 250 – 253!
Answer the following questions in your JOURNAL:
What is Cancer and what causes it?
Can cell division be turned on and off?
What does Cyclin do?
What are stem cells?
Do you believe stem cell research should be allowed? Briefly support your answer

18. Modeling the Phases of the Cell Cycle (pg. 254)