1. Cell Cycle and Mitosis Page: 51 and 52

2. What is the cell cycle?
Continuous sequence of events that takes place in eukaryotic cells
Starts when a cell is formed
Continues until cell has divided into 2 new cells

3. Interphase Longest phase of the cell cycle
Cells are metabolizing and growing
3 parts: G1 S G2

4. Interphase: G1 G1 = growth phase 1 Growth and metabolism
Draw picture of Interphase – Label 1) Cell Membrane = Outer layer of the cell; 2) Nuclear membrane = Layer around the light purple circle 3) Chromatin = stringy looking inside of nucleus; 4) Centrioles = Yellow cylinders

5. Interphase: S
S = synthesis
DNA is replicated (doubled)

6. Interphase: G2 G2 = growth phase 2 Slower growth and metabolism
Organelles duplicated
Preparing for cell division

7. Interphase: G0 G0 phase = Resting phase
Not dividing or preparing to divide
May reenter the G1 cycle, but often it continues in G0 until the organism dies

8. Mitosis

9. Mitosis
Mitosis is normal cell division, creates two identical cells. Cell division occurs throughout your life.
Three reasons why multicellular organisms do mitosis: Growth Repair Replacement

10. Why would a Unicellular organism do cell Division?
To reproduce!

11. Prophase - “primary = 1st”
Chromosomes condense and become visible
Nuclear membrane breaks down to let chromosomes out
Centrioles and spindle fibers move chromosomes opposite towards poles
Draw prophase: Label 1) Nuclear membrane = Dotted Circle; 2) Spindle Fibers = string/spider looking structures 3) Condensed Chromosomes = blue and red structures

12. Metaphase “Think Middle”
Chromosomes line up along equator
Spindle fibers firmly attach to centromeres .
. . . .
Draw Metaphase 1) Label Centromeres = Black dots in middle of chromosomes

13. Anaphase “Away” Centromeres break Chromatids move to poles
Guided/pulled by spindle fibers
Draw Anaphase: Label 1) Chromatids = V –shaped 2) Spindle Fibers = lines pulling 3) Centromeres = broken, being pulled by spindle fibers

14. Telophase “two” Chromosomes reach poles
Spindle fibers and centrioles disappear
Nuclear membrane forms and nucleus reappears
Chromosomes uncoil and disappear
Draw Telophase - Label: 1) Nuclear membrane reforming 2) Chromosomes uncoiling

15. Cytokinesis = 2 identical daughter cells
Cytoplasm divided between cells
New cell membrane forms in animal cells
New cell wall forms in plant cells
Result: 2 identical diploid cells
Diploid = 2 sets of chromosomes
Haploid = 1 set of chromosomes
Draw 2 identical daughter cells - Label: 1) Cell Membrane (2 cell membranes around each cell) 2) Nuclear membrane = dotted circle 3) Chromatin = string looking structures inside nucleus

16. Summary of Mitosis Prophase: Metaphase Anaphase Telophase
Chromosomes condense
Nuclear envelope disappears
centrosomes move to opposite sides of the cell
Spindle forms and attaches to centromeres on the chromosomes
Metaphase
Chromosomes lined up on equator of spindle
centrosomes at opposite ends of cell
Anaphase
Centromeres divide: each 2-chromatid chromosome becomes two 1-chromatid chromosomes
Chromosomes pulled to opposite poles by the spindle
Telophase
Chromosomes de-condense
Nuclear envelope reappears
Cytokinesis: the cytoplasm is divided into 2 cells

17. Vocab review: pg. 46 from ISN
Spindle Fibers = attach to centromeres to pull chromosomes apart
Nuclear membrane = stores chromosomes; must dissolve to let chromosomes move
Chromatin = DNA in its uncondensed form

18. Vocab review: pg. 46 from ISN
Histone Proteins = Used to wind up chromatin to form chromosomes
Chromosomes = condensed DNA; Contains 2 copies of chromatids
Chromatids = replicated chromosomes
Daughter cells = result of mitosis;
2 identical cells