1. Purpose of the Cell Cycle

2. Why are Cells so Small?
With your table, think about why cells need to grow and divide?

3. Cell Growth and Division
Cell division occurs in all living organisms
2 Types of living organisms
Prokayotes-unicellular organisms
Bacteria
Eukaryotes- multicellular organisms
Plants and animal

4. Prokaryotes reproduce through cell division

5. Cell division in Eukaryotes
Eukaryotes use cell division for specific function in an organism.
Cell division is involved in
Growth- how an organism gets larger
Development- makes specialized cells like nerve cells
Repair- heals wounds and injuries
Reproduction- creates sex cells for sexual reproduction.

6. Main reasons for ALL cells dividing
Gas and nutrient exchange- allows the organism to extract and produce energy to carry out the functions of life
2) DNA overload- allows for a lot of DNA to exist in the cell.
-DNA a molecule found in all living organisms that contains the directions an organism needs to grow, maintain itself and reproduce.

7. Cells division limits cell size
Why do we want cells to be small?
Allows more surface area to volume ratio.
EXAMPLE: What is the ratio of vowels to consonants in the alphabet?
5 vowels
21 consonants
Answer: 5:21 or 5 to 21 or 5/21

8. Surface to volume ratio
Amount of surface an object has to the amount of volume(space) it occupies. Formulas: Surface area=length x width x 6 (cube) Volume= length x width x height Surface area to volume = surface area/volume

9. Surface area to volume
Solve for each cube ?

10. What do you observe? Limits to cell growth
Increase cell size= more work for cell
Harder to transfer materials through the cells
DNA would fail to provide instructions

11. Cells grow, develop and repair
Growth
Large organisms has more cells
Small organisms have less cells

12. Development
Cells develop and become specialized to perform specific functions
Skin
Nerve
Muscle
Liver
Can you think of more?

13. repair
Cells help an organism body repair injury through cell division

14. Reproduce
Cellular division in sex cells through meiosis for fertilization to occur