1. Cell Division and Reproduction
Chapter 8.1

2. Why do cells go through cell division?
To grow
Organisms grow by ADDING more cells
To replace dead cells
All cells will die so they need to be replaced
To replace damaged cells
Cells will be damaged by injury (cut)

3. Definition of Cell Division
Cell division is the process of one cell dividing into two identical daughter cells

4. DNA - Hereditary Material
DNA is stored in a eukaryotic cells nucleus
Plant cells
Animal cells

5. What is Chromatin?
Loose (stringy) DNA in a cells nucleus is called chromatin
DNA before cell division
DNA ‘hanging out’

6. Chromosome doubles
Chromatin condenses (shrinks up) and doubles just before cell division
This forms a chromosome (X).
X X

7. What is a Chromosome?
A chromosome is a structure made up of DNA and protein in the nucleus of a eukaryotic cell

8. Cell Cycle
The cell cycle is the period of time from the beginning of one cell division to the beginning of the next.
The cell cycle has 3 parts:
Interphase See cycle on page 155
Mitosis
Cytokinesis

9. 1. Interphase First part of the cell cycle
Time in between cell divisions
Cell is on vacation
Longest phase. Most time is spent in interphase
At end, chromatin (stringy) doubles into a chromosome (X)

10. Mitosis Second part of the cell cycle Makes 2 new identical nuclei
Has 4 steps:
Prophase
Metaphase
Anaphase
Telophase

11. 2. Prophase First step of mitosis
Chromatin in nucleus coils into chromosomes (X’s)
Nuclear membrane begins to disappear

12. 3. Metaphase Second step of mitosis
Chromosomes line up in the middle of the cell
Spindle fibers attach to the chromosomes

13. 4. Anaphase Third step of mitosis
Chromosomes separate and begin to move to opposite ends of the cell

14. 5. Telophase Final step of mitosis
Two new nuclei form around the separated chromosomes
Chromosomes unwind to form chromatin
Mitosis ends

15. 6. Cytokinesis Final part of the cell cycle
Makes 2 new identical daughter cells
Shortest phase
END of the cell cycle

17. Cell Cycle Interphase Prophase Metaphase Mitosis Anaphase Telophase
Cytokinesis

19. Cell Cycle Mnemonic Write a mnemonic for cell division
(Ex. King Henry Died By Drinking Chocolate Milk.) I P
M Add a COLORED
A picture T C

20. Cell Cycle Mnemonic I
Played
Music At
The
Concert