1. The Cell Cycle & Cell Division

2. The Cell Cycle

3. Cell Cycle Allows single-celled organisms to reproduce themselves
Allows multi-cellular organisms to develop, grow, and maintain tissue
Has 4 stages
Gap 1 (G1)
Synthesis (S)
Gap 2 (G2)
Mitosis (M)

4. Gap 1 (G1) Cell enters cell cycle and nearly doubles in size
All important components in cytoplasm (mitochondria & other organelles) double in #

5. Synthesis (S)
Cell creates an exact copy of its DNA

6. Gap 2 (G2)
Cell builds machinery for cell division

7. Interphase G1, S, G2 phases are collectively know as interphase
Cell makes necessary preparations for cell division

8. Animated Cycle

9. MITOSIS

10. Mitosis
The process of cell division which results in the production of two daughter cells from a single parent cell.
The daughter cells are identical to one another and to the original parent cell.

11. Mitosis can be divided into stages
Interphase (G1, S, G2)
Prophase
Metaphase
Anaphase
Telophase & Cytokinesis

12. Interphase The cell prepares for division
Animal & Plant Cells
DNA replicated
Organelles replicated
Cell increases in size

13. Interphase Plant Cell Animal Cell
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14. Prophase The cell prepares for nuclear division
Animal & Plant Cells
Packages DNA into chromosomes
Becomes clear that 2 identical sister chromatids are attached at the centromere

15. Prophase Plant Cell Animal Cell
Photographs from:

16. Metaphase The cell prepares chromosomes for division
Animal & Plant Cells
Chromosomes line up at the center of the cell
Spindle fibers attach from daughter cells to chromosomes at the centromere

17. Metaphase Plant Cell Animal Cell
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18. Anaphase The chromosomes divide
Animal & Plant Cells
Spindle fibers pull chromosomes apart
½ of each chromosome (called chromotid) moves to opposite poles of the cell

19. Anaphase Plant Cell Animal Cell
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20. Telophase The cytoplasm divides
Plant Cell
DNA spreads out
2 nuclei form
New cell wall forms between the nuclei to form the 2 new daughter cells
Animal Cell
DNA spreads out
2 nuclei form
Cellular membrane pinches in to form the 2 new daughter cells

21. Telophase Plant Cell Animal Cell
Photographs from:

22. Mitosis Animation

23. Animal Mitosis -- Review
Interphase                                                             
Prophase                                                             
Metaphase                                                             
Anaphase                                                             
Telophase                                                             

24. Plant Mitosis -- Review
Interphase                                                             
Prophase                                                             
Metaphase                                                             
Anaphase                                                             
Telophase                                                             

25. MEIOSIS

26. One parent cell produces four daughter cells.
Meiosis
Meiosis is the type of cell division by which germ cells (eggs and sperm) are produced.
One parent cell produces four daughter cells.
Daughter cells have half the number of chromosomes found in the original parent cell

27. During meiosis, DNA replicates once, but the nucleus divides twice.

28. First Division of Meiosis
Prophase 1: Each chromosome duplicates and remains closely associated. These are called sister chromatids.
Metaphase 1: Chromosomes align at the center of the cell.
Anaphase 1: Chromosome pairs separate with sister chromatids remaining together.
Telophase 1: Two daughter cells are formed with each daughter containing only one chromosome of the chromosome pair.

29. Second Division of Meiosis
Prophase 2: DNA does not replicate.
Metaphase 2: Chromosomes line up at the center of the cell
Anaphase 2: Centromeres divide and sister chromatids move separately to each pole.
Telophase 2: Cell division is complete.
Four haploid daughter cells are formed.

30. Meiosis

31. Meiosis Animation

32. Differences in Mitosis & Meiosis
Asexual
Cell divides once
Two daughter cells
Genetic information is identical
Meiosis
Sexual
Cell divides twice
Four haploid daughter cells
Genetic information is different

33. Comparison Animations