1. “And the day came when the risk to remain tight in a bud was more painful than the risk it took to blossom” ~ Anis Nin Friday, October 10, 2013 S.C. Standards for Today: B-2: The student will demonstrate an understanding of the structure and function of cells and their organelles. Today’s Objectives: Review Quiz on Transport Cell Surface-to-Volume Ratio Cell Cycle Introduction Cell Mitosis and Cytokinesis Activity Reminder: Cell Project Due 10/16/13! Warm Up: What happens if one cell dies on your hand or foot? Does every cell die? Does your foot fall off? What does the body do in order to replace dead cells?

3.  Draw a large circle on your page  Divide into 4 parts like this:

4. Interphase: G 1 Phase (Growth) S Phase (Synthesis) G 2 Phase (Growth) M Phase (Mitosis) Prophase Metaphase Anaphase Telophase Cytokinesis G 0 No division will take place G1G1 S G2G2 P MAT C G0G0

7.  Why should cells divide?  Maintenance and Repair ▪ If you cut your finger, it doesn’t stay like that!  DNA Functioning ▪ When a cell grows, it doesn’t produce more DNA  Nutrients and Wastes Movement ▪ The cell has to move

8.  G1 Phase  Cell grows, makes proteins  S Phase  DNA replicates (synthesizes)  G2 Phase  Growing, getting ready for cell division

10.  P  Prophase chromosomes  Chromatin condenses into chromosomes, becomes visible  Nuclear membrane  Nuclear membrane disappears  Centrioles  Centrioles separate to opposite poles  Spindle fibers  Spindle fibers form, grow toward center  Longest phase (50-60% of mitosis)

12. Interphase CHROMATIN  In Interphase, DNA in long thin threads, called CHROMATIN. Here, in S phase, they duplicate (replicate, synthesize) CHROMATIN Chromosomes  As Prophase begins, CHROMATIN winds up (condenses) into Chromosomes.  Made of two sister Chromatids, joined at the Centromere.

14.  G1 Phase  Cell grows, makes proteins  S Phase  DNA replicates (synthesizes)  G2 Phase  Growing, getting ready for cell division

15. chromatin chromosomes This is interphase’s chromatin, long thin strands of proteins and DNA. Only later in mitosis’ beginning, Prophase, will this condense and coil up into the classic looking X shaped structures, termed chromosomes. Coiled chromosomes

17.  M  Metaphase  Chromosomes line up at cell’s equator  Spindle fibers connect to chrom.  Shortest phase of mitosis

19.  A  Anaphase  Centromeres that join the sister chromatids split  Sister chromatids separate, becoming individual chrom.  They now move to opposites sides of cell

21.  C  Cytokinesis: Cytoplasm division  In animals, cleavage furrow pinches cell in two.  In plants, a cell plate forms, becoming the new wall.

27.  You will be assigned a partner  You and your partner will work together to arrange the stages of Mitosis and Cytokinesis in the proper order  Let us know when you are finished!

28.  What type of cell division is responsible for the repair of your skin following a sunburn?  During which phase of the cell cycle does growth occur?  Which of the following is true regarding prophase?