1. Unit #6 - The Cell Cycle The white sections summarize key information and vocabulary terms are underlined.

2. Dreams I look to the sky and what do I see? A castle, a rainbow, and dreams for me, An end to this battle that I must fight, To rid my feelings of depression and fright, An end to cancer is not far away, It will be here someday... someday.cancer ~ Anonymous

3. Observations

4. Introduction Textbook Reference pg. 204-206 Much as your body goes through different stages in your life, the cells and viruses do too. The life cycle of the cell is known as the cell cycle. In this unit we will discuss the processes of the cell cycle (the making of new cells). http://www.wadsworth.org/BMS/SCBlinks/ mcewen/Media/fig_1_cell_mitosis.jpg

5. 5 Reasons Cells Divide Textbook Reference pg. 203 1.Growth- an organism will increase in size as the number of cells making up that organism increase 2.Differentiation- cells develop specialized cells to carry out specific tasks ex: the heart cell versus the muscle cell 3.Repair- to repair lost or damaged cells ex: mending of skin, blood vessels and bone 4.Regeneration- ability to replace a lost limb or body part by rapid cell division ex: starfish, lizard

6. 5 Reasons Cont. And finally… 5.Reproduction – the making of a new organism http://ghr.nlm.nih.gov/handbook/illustrations/mitosismeiosis;jsessionid=B368026AB01 E981849F2E31603F7154F

7. Cell Division The splitting of a single cell into two new daughter cells is called cell division. This will occur when a cell reaches it’s maximum size and the nucleus initiates cell division; proteins called cyclins and enzymes begin this process. http://protist.i.hos ei.ac.jp/PDB/Ima ges/Sarcodina/H eliozoa/Actinosph aerium/cell_divisi on_1.jpg

8. Two Types of Cell Division Textbook Reference pg. 204-206 Mitosis- the division of body cells (somatic) due to the splitting of the nucleus to create two new cells. Meiosis – the creation of gametes (sex cells) by cutting the # of chromosomes in half to create sex cells. http://ghr.nlm.nih.gov/handbook/illustrations/mitosi smeiosis;jsessionid=B368026AB01E981849F2E3 1603F7154F

9. Chromosomes Textbook Reference pg. 203-204 In order for a cell to survive, the genetic information is needed. Cells tightly coil their DNA into chromosomes during the process of mitosis. Review: We have already learned that genetic information is held within the nucleus (of Eukaryotes) in the form of DNA. Therefore, it is very important that cells must copy their genetic information before dividing. http://www.koshland-science- museum.org/exhibitdna/images/ dna/intro02.gif

10. Chromosomes Cont. http://www.learner.org/channel/courses/biology/images/archive/fullsize/1940_fs.jpg

11. Chromosomes Cont. During mitosis, identical chromosomes pair up and are now called sister chromatids (1), held together by a centromere (2). Sketch it! http://upload.wikimedia.org/wikipedia/e n/5/54/Chromosome.png

12. Stage #1 Interphase Textbook Reference pg. 204-205 1.Interphase = The period of growth for the cell before cell division (the longest stage) which is broken up into the following phases: G 1 – growth and development S – copies of the DNA G 2 – the cells organelles and centrioles (in animals only) copied http://dedunn.edublogs.org/files/2011/06/mi tosis-26hzktr.jpg

13. Knowledge Check During the course of the life of a cell, there is a complicated series of checkpoints to ensure that everything is going according to plan.

14. Stage #2 Prophase Textbook Reference pg. 206-208 2.Prophase = The DNA condenses and forms chromosomes. Identical chromosomes (Xsomes) join Nucleus disappears Centrioles (the organelles which form the spindles) move to opposite poles Spindle fibers (long strings that help the cell divide) begin to grow http://dedunn.edublogs.org/files/2011/06/mi tosis-26hzktr.jpg

15. Stage #3 Metaphase Textbook Reference pg. 208 3.Metaphase = Xsomes pairs line up along the middle of the cell on the the metaphase plate Centrioles have moved to the poles; spindle fibers are still attached to chromosomes. http://dedunn.edublogs.org/files/2011/06/mitosis- 26hzktr.jpg

16. Metaphase Cont. http://student.ccbcmd.edu/courses/bio141/lecguide/unit6/genetics/DNA/DN Arep/images/metaphase1_pc.jpg

17. Stage #4 Anaphase Textbook Reference pg. 208 4.Anaphase = The centromeres divide and spindle fibers pull the chromosomes apart from their partners The chromatids move to opposite poles of the cell http://dedunn.edublogs.org/files/2011/06/mitosis-26hzktr.jpg

18. Stage #5 Telophase Textbook Reference pg. 209 5.Telophase = The nuclei reform at each end of the cell Chromosomes uncoil into chromatin (or loose genetic material) Spindles release Xsomes and shorten. The cell begins to pinch as the cytoplasm begins to divide http://dedunn.edublogs.org/files/2011/06/mitosis- 26hzktr.jpg

19. Stage # 6 Cytokinesis Textbook Reference pg. 209 6.Cytokinesis = In animals, the cell membrane is drawn inward (cleavage furrow). In plants, a cell plate is built to create new cells walls and membranes. Each half has one nucleus and gets own set of centrioles (and other organelles) The cell is pinched in half until membrane meets. The cell is now two and enters Interphase (G1). Animation http://alevelnotes.com/content_image s/i77_dwa_1_mitosis.gif

20. “During mitosis, after all the genetic material is sorted out, the cell splits all of its cytoplasmic goodies in two and sends them to opposite ends. It then constricts in the middle and eventually ‘pinches’ in half, producing two daughter cells. The location at which the pinching in occurs is known as the cleavage furrow.” Imagemitosiscytoplasmic goodiesImage Cytokinesis Cont.

21. Visualizing Mitosis http://wiki.district87.org/images/9/9f/Plant_cells.jpg Prophase InterphaseMetaphase Anaphase Telophase

22. Ex Mnemonics Ms. Flores’s Example: I = “I’ll P = probably M = make A = apple T = tarts for C = Christmas!”

23. Student Created Example: I = “Intelligent P = people M = make A = all T = the C = cash!”

24. The word “mnemonic” means “memory tool”. It is a phrase or saying to remember a list. Student Created Example: I = “Irritating P = pupils M = make A = all T = teachers C = cringe!” The mnemonic goes on the outside of the flap and the actual stage goes on the inside of the flap.

25. In Conclusion At the beginning of the unit, we discussed how cancer relates to mitosis.cancer Cancer is thought to be caused by a change in the controlling genes that regulate the cell cycle. Mitosis is the division of somatic body cells to create identical daughter cells. http://buffonescience9.wikispaces.co m/file/view/Mitosis-Animation- 1.gif/294684052/236x228/Mitosis- Animation-1.gif