1. More doesn’t mean better OR more advanced

2. Cell Division
Chapter 3 Section 3

3. There are over 100 trillion cells in the body!
We all started out as a single cell, so how did we get so many????
Through a process of cell division.

4. Mitosis & Cell Division

5. Parts of a chromosome (pg. 105)
Chromosomes are structures in the nucleus that contains DNA, the hereditary material of life.
Draw and label on back of booklet.

6. How do cells divide? By going through the cell cycle.
The cell’s life cycle is called the cell cycle.
The amount of time for this is different for different types of cells.

7. Cell cycle

8. Why is this important? This is important for growth.
This is important for repair.
This is important for replacement of cells.
Some one-celled organisms reproduce by cell division.
Write this: Cell Cycle is important for:
*Growth *Repair *Reproduction

9. Cell Cycle

10. What is it? The cell cycle is the “life cycle” of the cell.
It occurs in phases that include periods of regular cell function and periods of cell division.
It happens in all somatic (body) cells.

11. What is it?

12. interphase Cells spend 90% of its time in this phase.
What happens?
Cells spend 90% of its time in this phase.
Performs normal functions
Grows
Chromosomes are copied/doubled
Prepares for cell division

13. interphase
What happens?

14. mitosis

15. What is it?
Mitosis is the cell division stage of the cell cycle in which one mother cell creates two identical daughter cells.
It happens in all somatic (body) cells.

16. What is it?

17. prophase Mitosis begins: Nuclear membrane dissolves
What happens?
Mitosis begins:
Nuclear membrane dissolves
Centrioles move to the opposite ends of cell (poles)
Spindle fibers form and attach pairs
Chromosomes pair up, condense and appear visible

18. prophase
What happens?

19. metaphase
What happens?
Chromosome pairs line up at the center of the cell (equator).
Spindle fibers attach to the chromosomes at the centromeres.
Think: Meets in the Middle

20. metaphase
What happens?

21. Anaphase
What happens?
Chromosome pairs (sister chromatids) separate and move to opposite ends of the cell.
Think: move Away from the center

22. Anaphase
What happens?

23. Telophase Two new nuclei form Chromosomes change to chromatin
What happens?
Two new nuclei form
Chromosomes change to chromatin
(Threads rather than rods)
Mitosis Ends
Think: Two new nuclei

24. Telophase
What happens?

25. cytokinesis The cytoplasm splits in two Cell division is complete
What happens?
The cytoplasm splits in two
Cell division is complete
Different process for plants:
Cell wall forms in the center between the nuclei
Animals: cell membrane pinches in

26. cytokinesis
What happens?