1. Cell Division: Mitosis
Licentious division - prostate cancer cells during division.

2. Interphase Three Stages G1: First growth phase
S: DNA replication (S = synthesis)
G2: Second growth phase
After Interphase, Mitosis starts (cell division)

3. CELL CYCLE VIDEO

4. MITOSIS MITOSIS IS JUST ONE SMALL PART OF THE ENTIRE CELL CYCLE.
Definition: Mitosis is the process by which a eukaryotic cell separates the chromosomes in its cell nucleus into two identical sets in two nuclei.

5. KEY CONCEPT Cells divide during mitosis and cytokinesis.

6. Chromosomes condense at the start of mitosis.
DNA wraps around proteins (histones) that condense it.
DNA double helix
DNA and histones
Chromatin
Supercoiled DNA

7. DNA plus proteins is called chromatin.
chromatid
telomere
centromere
Condensed, duplicated chromosome
One half of a duplicated chromosome is a chromatid.
Sister chromatids are held together at the centromere.
Telomeres protect DNA and do not include genes.

8. Mitosis and cytokinesis produce two genetically identical daughter cells.
Parent cell
centrioles
spindle fibers
centrosome
nucleus with
DNA
Interphase prepares the cell to divide.
During interphase, the DNA is duplicated.

9. Mitosis divides the cell’s nucleus in four phases.
During prophase, chromosomes condense and spindle fibers form.

10. Mitosis divides the cell’s nucleus in four phases.
During metaphase, chromosomes line up in the middle of the cell.

11. Mitosis divides the cell’s nucleus in four phases.
During anaphase, spindle fibers pull sister chromatids to opposite sides of the cell.

12. Mitosis divides the cell’s nucleus in four phases.
During telophase, new nuclear membranes form and chromosomes begin to uncoil.

13. During Cytokinesis the cell divides into two daughter cells

14. STAGES OF MITOSIS INTERPHASE EARLY PROPHASE LATE PROPHASE METAPHASE
CYTOKINESIS
(daughter cells formed)
ANAPHASE
TELOPHASE

15. Why is it important for cells to make perfect copies of themselves?
Their daughter cells need to be able to do the same thing they do. Muscle cells need to be muscle cells. Skin cells need to be skin cells, etc.
If DNA is copied or separated incorrectly, cell won’t be able to function correctly.

16. How do chromosomes move during mitosis?
By using spindle fibers!
Let’s take a look at this in more detail…

17. The Spindle
A spindle is a web type structure made up of microtubule fibers. It is essential for mitosis because it arranges the chromosomes into their correct positions in preparation for cell division.
Mitotic center
Click the return button to return to the prophase slide. Or the house button to return to the main menu.
The purpose of the spindle is to organise the chromosomes during mitosis. It is a cradle of microtubule fibres which cause constriction around the centre of the cell, causing the cytoplasm to split.
A cell at metaphase
a spindle
Microtubule 17

18. Mitosis in Action Blue shows DNA, green shows spindle fibers.
interphase
early prophase
late prophase
prometaphase
Blue shows DNA, green shows spindle fibers.
metaphase
early anaphase
late anaphase
late telophase

19. Video of mitosis in process in actual cells

20. Comparing plant/animal cell mitosis.
While you observe the next set of images, try to identify how these processes differ in plant and animal cells. Why do you think the images are so different?
Cytokinesis is different in plant and animal cells
In animal cells, the membrane pinches closed.
In plant cells, a cell plate forms.

21. In animal cells, a cleavage furrow forms and separates daughter cells
Cleave furrow in a dividing frog cell.

22. The plant cell wall forces cytokinesis to play by different rules

23. Microscopy Video of Mitosis in an Animal Cell
Microscopy Video of Mitosis in a Plant Cell