1. MITOSIS
the key to growth

2. Mitosis - the division of the nucleus into two equal sets of genetic information
Basically, simple cell division

3. Mitosis is part of the Cell Cycle
The cell cycle is divided into 5 phases.
1. Interphase
2. Prophase
3. Metaphase
Mitosis
4. Anaphase
5. Telophase
**This is a moving, continuous process. Stages are for study.

4. Period of growth and normal cell activity
Interphase
Period of growth and normal cell activity
Events of Interphase:
90% of the cell life.
DNA is in the form of chromatin.
DNA replicates, making two exact copies of each chromosome.
2 centrioles appear.
Stages of interphase:
G1 (Gap 1) – normal cell growth
S (Synthesis) – DNA synthesis (replication)
G2 (Gap 2) – prepares for cell division

5. Interphase
Look for a distinct nucleus

6. Mitosis: Prophase Three things happen:
Chromatin coils and become visible chromosomes.
The nuclear membrane breaks down and disappears
The spindle fibers & centrioles forms

7. Mitosis: Prophase
Look for chromosomes in the center

8. Mitosis: Metaphase
Chromosomes line up on the “equator” (in the middle of the cell)
Chromatids attach to the spindle fibers at the centromere

9. Mitosis: Metaphase
Look for chromosomes lined up on the “equator”

10. Mitosis: Anaphase
Chromosomes pull apart in opposite directions towards the “poles”
This phase ends when the chromosomes reach the poles.

11. Mitosis: Anaphase
Look for chromosomes in two groups pulling apart

12. Mitosis: Telophase The fourth and final phase of mitosis
The opposite of Prophase
Chromosomes unwind to form chromatin
Two new nuclei form with new membranes
The spindle disappears

13. Mitosis: Telophase
Look for two groups of chromosomes with a cell plate or cleavage furrow

14. Cytokinesis The division of the cytoplasm
Animal cells pinch inward forming a cleavage furrow.
Plant cells divide from the inside towards the outside by forming a cell plate which becomes the cell wall.

15. Cytokinesis
Animals:
Cleavage furrow
Cell plate cell wall

17. Animals Plants Differences in plant and animal cells: centrioles
summary
Animals
Plants
centrioles
no centrioles
cleavage furrow
cell plate
cell wall