1. Chapter 10
Cell Growth & Division

2. Question of the Day
What is the size of one individual cell - Plant & Animal?
On average an animal cell is 10 m and a plant cell is 100m.
1 m = 1x10^-6m

3. 10-1 Cell Growth How does a cell grow?
Through mass & organelle production
Problems with unlimited growth
How big can a cell get before it gets bad?
Materials are harder to exchange thru membranes if bigger
Waste Products
Oxygen
Water

4. Ratio of Surface Area to Volume
What are Surface Area (SA) & Volume (Vol)?
Surface Area = L x W x 6 sides
Volume = L x W x H
High SA to Vol makes it easier to exchange things
As the cell grows, SA and Vol get bigger
Bigger cells, Ratio of SA to Vol gets smaller

5. Cell Division Before cell gets too big it divides
Forms 2 daughter cells
Two cells are identical copies
Complete with DNA, organelle, cytoplasm & equal size

6. Types of Cell Division In Prokaryotes - Simple, 1 step division
In Eukaryotes -
Complex, 2 stages:
Mitosis
(nucleus divided)
Cytokinesis
(cytoplasm ÷)

7. Chromosomes What is a chromosome? What carries genetic information
How many does a human have? 46
What forms when chromosome ÷
sister chromatids (identical)
How are chromatids attached?
Centromere

8. The Cell Cycle There are 4 phases to cell cycle
1st 3 are growing and duplicating & 4th is division
1st is G1 - (Growth) of Cell
2nd is S - (Synthesis) DNA duplication
3rd is G2 - (Growth) & Mitosis Prep
4th is M - (Mitosis) Cell Division

9. Cell Growth Phases Also called Interphase G1 - initial phase
cell almost doubles in size
S - 1/2 way thru
chromosomes replicate
G2 - prep for mitosis
finishes growth, ready for mitosis
Takes about 95% of the time for division

10. Mitosis (Cell Division)
4 Phases of Mitosis
Prophase
Longest phase centrioles, spindle appear, nucleus dissolves
Metaphase
Chromosomes lineup, spindles attach to centromere
Anaphase
Spindles pull chromatids apart
Telophase
2 Nuclei reform around chromatids, spindles break
Cytokinesis
Organelles & cytoplasm split & cell membrane divides

11. 10-3 Regulating Cell Cycle
What controls cell division?
Cyclins
What are they?
Protein that helps spindle form
Regulates timing of cell cycle
In 2 ways:
Internally - proteins affect mitosis inside cell
Need all chromosomes to be doubled & attached to spindle
Externally - proteins that speed up, slow down mitosis outside
Stimulate cell growth (cytoplasm, cell membrane, organelles)

12. Uncontrolled Cell Growth
What is it called?
Cancer
Cells that don’t respond to growth stop signs
What do groups of cancer cells form?
Masses or Tumors
What kind of cancers are there?

14. Stem Cells What are they?
Unspecialized cells that can be changed into any cell.
Why is it so controversial?
Deals with embryonic cells usually.

15. Ch. 10 Review What are the essential questions?
What is surface area to volume ratio?
What is cell division/ cycle/mitosis?
What are cell cycle regulators?
What are cancer and stem cells?