1. The Cell Cycle & Mitosis
BIOLOGY 12
The Cell Cycle & Mitosis

2. The Cell Cycle
Animation of Cell Division

3. The Cell Cycle
a series of events that cells go through as they grow and divide
a cell grows
prepares for division
divides to form two daughter cells, each of which begins the cycle again

4. The Cell Cycle Interphase Mitosis Cytokinesis G1 phase S phase
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis

5. Interphase most of the cell’s time is spent in Interphase
the period of growth between cell divisions
during Interphase the cell will:
increase in size
synthesize new proteins and organelles
undergo DNA replication

6. Interphase G1 Phase S Phase G2 Phase
gap phase after mitosis, cell growth
S Phase
DNA replication (synthesis)
G2 Phase
gap phase, preparation for mitosis

7. Mitosis
process where chromosomes are duplicated and distributed to daughter nuclei
each daughter nucleus carries the same set of genetic information as the parent nucleus

8. Mitosis

9. Prophase first and longest phase
the centrioles separate and take up position on either side of the nucleus
spindles and spindle fibres begin to form

10. Prophase the chromatin condenses into chromosomes
chromosomes join at the centromere
the nuclear envelope breaks down

11. Prophase Spindle forming Centrioles Chromosomes (paired chromatids)
Centromere

12. Metaphase
the chromosomes line up at the metaphase plate (center of the cell)
microtubles connect the centromere of each chromosome to the poles of the spindle

13. Metaphase
Centromeres
Centrioles

14. Anaphase chromosomes separate
sister chromatids move towards opposite poles

15. Anaphase
Chromatid (or individual chromosomes)

16. Telophase final stage of mitosis
chromosomes gather at opposite ends of the cell and lose their distinct shape
nuclear membrane begins to reform

17. Telophase
Nuclear Membrane

18. Cytokinesis
the final stage of the Cell Cycle, but begins during telophase
division of the cytoplasm and organelles of a cell into two daughter cells

19. Cytokinesis in Animal Cells – the plasma membrane pinches together
in Plant Cells – the cell plate grows outward from the middle
each daughter cell is an exact replica of the mother cell

20. Cytokinesis

21. The Cell Cycle
Animation of Interphase and Cell Division

22. Animal vs Plant Cells Animal Cells: Plant Cells: have centrioles
cytoplasm pinches in during cytokinesis
can divide anywhere, at any time
Plant Cells:
no centrioles
cell plate forms from center
division found in areas called meristems

23. Plant Cells

24. Questions
What do you call the genetic information in each phase of the cell cycle?
Why is it more accurate to call mitosis "nuclear replication" rather than "cellular division"?
Draw a plant cell in one stage of Mitosis and label it.
What role does the spindle play in the cell dividing?
When and where does the cellulose wall (cell plate) form in the mother cell?
How can you differentiate prophase from metaphase?
What cellular events occur during interphase?
Compare cytokinesis of animal cells with that of plant cells.
Compare and contrast prophase and telophase.