1. Cell Division
By: Mr. Kauffman

2. Outline Cells Review What is cell division? Mitosis 4 Steps of Mitosis
Results of Mitosis
Meiosis
8 Steps of Meiosis
Results of Meiosis
2 Types of Cell Division

3. Cells Review
Cell: smallest part of any living thing that carries out the functions necessary to support life
Unicellular organism: living thing made up of 1 cell
Multicellular organism: living thing made up of many cells

4. What is cell division? Cell division: a way to produce more cells
Usually 1 cell divides to make 2 cells
Why is cell division important to multicellular organisms?
Its how they grow
Replace cells that have died
Cancer cell dividing

5. What is cell division?
Why is cell division important to unicellular organisms?
Its how they reproduce
E. Coli cell dividing

6. Mitosis
Mitosis: process when the cell divides to form 2 identical cells
Produces normal body cells
Skin and muscle cells
The cells produced are identical to each other and to the original cell

7. Mitosis Mitosis has 4 steps: 1. Prophase 2. Metaphase 3. Anaphase
4. Telophase

8. 4 Steps of Mitosis Prophase 1st step Nucleus disappears
Chromosomes form (look like X’s)
These are how the DNA is stored in our cells

9. 4 Steps of Mitosis Metaphase 2nd step
Chromosomes are lined up in the middle of the cell

10. 4 Steps of Mitosis Anaphase 3rd step Chromosomes are pulled apart
½ of each chromosome goes to each end of the cell

11. 4 Steps of Mitosis Telophase 4th step
The cell begins pinching in at the middle
Eventually the 1 cell splits to form 2 cells
Process is known as cytokinesis
Each new cell has its own nucleus and DNA

12. Results of Mitosis Mitosis produces normal cells in the body
Skin and muscle cells
1 cell splits to form 2 cells
The new cells are identical to each other (same DNA)
The new cells are also identical to the original cell (same DNA)

13. Meiosis Meiosis: cell division that produces reproductive cells
Reproductive cells are also called gametes
2 basic types of gametes (reproductive cells)
Females – egg cells
Males – sperm cells

14. Why Meiosis is Needed
Fertilization: combining of sperm and egg cells to form a zygote
the zygote then grows and develops into a new organism

15. Meiosis Meiosis has 8 steps Basically goes through mitosis twice
There are 2 cell divisions

16. Meiosis 8 Steps of Meiosis Prophase 1 Metaphase 1 Anaphase 1
Telophase 1
Prophase 2
Metaphase 2
Anaphase 2
Telophase 2

17. Results of Meiosis Meiosis produces reproductive cells (gametes)
Sperm and egg cells
1 cell splits to form 4 cells
The 4 new cells have ½ of the DNA that the original cell had
Haploid cells: cells with ½ of the amount of DNA of a normal cell
Diploid cells: cells with the normal amount of DNA

18. 2 Types of Cell Division in Humans
Mitosis
Characteristics
Meiosis
Normal body cells
(skin and muscle)
Types of cells produced
Reproductive cells
(egg and sperm) 4
# of steps 8
PMAT
Step names
PMAT (1 and 2) 2
# of cells produced 4
46 (single)
# of chromosomes in cells
23 (single)
Identical (same DNA)
Comparison to original cell
½ the DNA

19. 2 Types of Cell Division in Humans