1. Mitosis

2. Mitosis division of the nucleus only occurs in eukaryotes
has four stages
doesn’t occur in some cells such as brain cells

3. Four Mitotic Stages
Prophase
Metaphase
Anaphase
Telophase
PMAT!

4. Early Prophase
chromatin in nucleus condenses to form visible chromosomes
spindle forms from fibers in cytoskeleton or centrioles (animal)
Cytoplasm
Nucleolus
Nuclear Membrane
Chromosomes

5. Late Prophase nuclear membrane & nucleolus are broken down
chromosomes continue condensing & are clearly visible
spindle fibers attach to the centromere of each chromosome
spindle finishes forming between the poles of the cell

6. Nucleus & Nucleolus have disintegrated
Late Prophase
Chromosomes
Nucleus & Nucleolus have disintegrated

7. Sketch The Spindle
Centromere
Centriole
Spindle fiber

8. Metaphase
chromosomes, attached to the spindle fibers, move to the center of the cell
chromosomes are now lined up at the equator
Equator of Cell
Pole of the Cell

9. Chromosomes at Equator
Metaphase
Spindle fibers
Chromosomes at Equator

10. Metaphase spindle fibers spindle fibers
chromosomes lined at the equator
chromosomes lined at the equator

11. Anaphase occurs rapidly
chromatids are pulled apart to opposite poles of the cell by spindle fibers

12. chromatids being separated
Anaphase
chromatids being separated
chromatids being separated

13. Telophase chromatids at opposite poles spindle disassembles
nuclear envelope forms around each set of chromatids to make two nuclei
nucleolus reappears in new nuclei
chromosomes reappear as chromatin

14. chromatids now back as chromatin

15. Cytokinesis means division of the cytoplasm
division of cell into two, identical halves called daughter cells
in plant cells, cell plate forms at the equator to divide cell
in animal cells, belt of protein fibers splits the cell

16. Cytokinesis
belt of fibers in animal cell
cell plate in plant cell

17. Daughter Cells of Mitosis
have the same number of chromosomes as each other & as the parent cell from which they were formed
identical to each other, but smaller than parent cell
must grow in size to become mature cells (G1 of Interphase)

18. Review of Mitosis

19. Name the Stages
Interphase
Prophase
Telophase
Metaphase
Anaphase

20. Early, Middle, & Late Prophase?
Early, Middle, & Late Prophase ? ? ?
Metaphase
Anaphase
Late Prophase ? ? ?
Late Anaphase
Telophase
Late Telophase

21. Uncontrolled Mitosis
if mitosis is not controlled, unlimited cell division – this is cancer
masses of cancer cells cause tumors which invade surrounding healthy tissue
not all tumors are cancerous – some DON’T invade healthy tissue
cancer cells