1. Mitosis

2. Objective: I can identify and describe the stages of mitosis.
Warm Up: What makes a cancer cell so dangerous?

3. Cell life cycle: changes cell goes through from time formed until it divides
2 major periods:
1. Interphase: cell grows and carries on usual metabolic activities
- longest phase of cycle
- very active
-DNA is duplicate toward end
2. Cell division: It reproduces itself
- fx : more cells for growth and repair processes

4. Interphase G1 Phase: synthesis of RNA and proteins .Period of
growth and development
for the cell.
S phase ( Synthesis): the
chromosomes of the cell
are copied
G2 Phase : cell grows in
Preparation for cell division).
Any repairs

5. Mitosis
Cells replicated Genetic material separates & cell prepares to split into two cells

6. Stages of Mitosis
4 Stages
Prophase
Metaphase
Anaphase
Telophase

7. Stages of Mitosis

8. Prophase- 1st stage Stage where dividing cells spend the most time
The cells chromatin tightens, or condenses into chromosomes
The chromosomes are shaped like an X
Each chromosome is a single structure that contains the genetic material

9. Prophase
Chromosomes become visible and condense becoming shorter and thicker
Each identical copy of a single chromosome is called a sister chromatid. The nuclear envelope breaks down and spindle fibers form as microtubules grow at the centrioles that move to opposite poles of the cell

10. Each half of this X is called a sister chromatid.
Sister chromatids- structures that contain identical copies of DNA
Centromere: structure at the center of the chromosome where the sister chromatids are attached
The centromere is important , it ensures that a complete copy of replicated DNA will be part of the daughter cells at the end of the cycle

11. Nuclear envelope breaks down
Microtubule structures called spindle fibers form in the cytoplasm
*in animal cells another pair of microtubule structures called centrioles migrate to the ends or poles of the cell.

12. -Spindle apparatus: spindle fibers, centrioles, and aster fibers ( whole structure) -Spindle apparatus: important in moving and organizing the chromosomes before cell division Near end of prophase- nuclear envelope seems to disappear. - spindle fibers attach to the sister chromatids of each chromosome on both sides of the centromere and then attach to opposite poles of the cell. -This arrangement ensures that each new cell receives one complete copy of the DNA

13. Metaphase- 2nd stage
Sister chromatids are pulled along the spindle apparatus toward the center and line up in the middle of the cell along the equatorial plate
One of the shortest stages

14. Anaphase- 3rd stage Chromatids pulled apart
Microtubules of the spindle apparatus begin to shorten
Sister chromatids separate into 2 identical chromosomes
All the sister chromatids separate simultaneously
At the end- the microtubules move the chromosomes toward the poles of the cell.

15. Telophase – Last stage
Chromosomes arrive at the poles of the cell and begin to relax, or decondense
A new nuclear membrane starts to form around each group.
Chromosomes uncoil, and the spindle disappears.

16. Cytokinesis 2 genetically identical cells Divide the cytoplasm
Results in 2 cells each with identical nuclei
2 genetically identical cells

17. T.O.D.
List the stages of Mitosis