Today is Monday, November 11 th , 2013 (T hank a) Veteran’s Day

1. In This Lesson: Mitosis and Cell Cycle (Lesson 2 of 3) Today is Monday,November 11th, 2013(Thank a) Veteran’s Day Pre-Class:So if everyone in this room started from one cell (the zygote - remember?), how did we all get so big? What’s that process called? Also, take note of the homework.

2. Today’s Topics • Cell Cycle • Mitosis • And maybe some rabbits… http://sajjadzaidi.com/2007/jan/giant_bunnies_for_breakfast/

3. Where is this in my book? • P. 241 and following…

4. Introducing this with a clip… • …from a short film. • i am so proud of you by Don Hertzfeldt (part of the feature film It’s Such a Beautiful Day) • Listen for the references to cells.

5. Aside: How Old are You? • Like in the short film clip, your cells really do get replaced every so often. • Some can complete a cycle in a day; others, like bacteria, can complete one on the scale of minutes. • What this means, however, is that you are older than any of the cells you have right now. • Your oldest cells right now are only between 7 and 9 years old.

6. The Cell Cycle • Cells have their own life cycles. • Divided into five phases that form a repeating loop: • G1 • S • G2 • Mitosis • Cytokinesis • Side note: The “G” stands for “Gap.”

7. The Cell Cycle http://www.treatgene.com/wp-content/uploads/2009/10/cellcycle3.jpg

8. The Cell Cycle • The Cell Cycle is really only 3 general steps: 1. Interphase: • G1 • The first growth phase. • S phase • Synthesis (DNA is copied - remember that?) • G2 • The second growth phase. • Nucleus prepared for division.

9. The Cell Cycle 2. Mitosis (sometimes called M phase): • The cell nucleus divides. • Chromosomes are separated. 3. Cytokinesis • The cytoplasm/membrane divides.

10. The Cell Cycle • One other note… • Some cells, like some muscle cells, don’t really divide. • We say they are in G0 stage.

11. The Cell Cycle • The cycle is regulated by proteins called cyclins. Interphase http://www.treatgene.com/wp-content/uploads/2009/10/cellcycle3.jpg

12. Interphase Steps • Checkpoints • End of G1 • During G2 • End of Mitosis • Checkpoints determine if the cell will go to the next step. • What happens if a checkpoint “breaks?”

13. Cancer • Uncontrolled cell divisionleads to some forms of cancer. • This is how tumors form. http://www.tc-cancer.com/images/img-cancer-cell.jpg

14. Normally Functioning Checkpoints • G1Checkpoint: • At the end of G1, if growth and original DNA is OK, start copying DNA in S phase. • G2Checkpoint: • Double-check that the DNA is OK, start mitosis. • Mitosis Checkpoint: • Exit mitosis, divide the cell, grow again.

15. Checkpoints http://skreened.com/scienceforscientists/dna-checks-itself-before-it-wrecks-itself

16. The Time Scale (Generally) http://www.uic.edu/classes/bios/bios100/lecturesf04am/lect16.htm

17. Time for a kindagame… • Grab yo’ laptops and find The Cell Cycle Game: • http://nobelprize.org/educational/medicine/2001/index.html • Complete the Quia activity called Cell Cycle Game • Keep an eye on the dial in the upper left corner and the “energy” in the upper right! • http://www.nobelprize.org/educational/medicine/2001/index.html

18. Healing • So, do cuts heal faster on babies or old people? • Babies!

19. More hybrid animals! • TED: Paul Wolpe – Questioning Bioengineering

20. Mitosis • Mitosis is the process by whichsomatic cells (body cells)replicate and divide. • [technically it’s just the nucleus dividing, but sometimes the names are used interchangeably] • What do I mean by this? • Start with one cell. • Cell copies all its DNA/chromosomes. • Chromosomes form an X-shape. • Cell divides. • Two daughter cells form.

21. And…the point? • Why do mitosis? • Growth • Repair • Differentiation (giving cells their jobs)

22. Chromosomes vs. Chromatids S Phase Chromosomes are copied Sister Chromatid Sister Chromatid Chromosome Chromosome Pre-S Phase Post-S Phase

23. Chromosome Vocabulary • Chromatid • Half of a duplicated (X-shaped) chromosome. • Prior to duplication, it was called a chromosome. • Sister Chromatids • The two identical chromatid copies that make up an X-shaped chromosome. • Centromere • The site at which the two sister chromatids join. • Basically the same as the kinetochore.

24. Chromosome Structure Sketch me! Sketch me! Sketch me! Sketch me! Sketch me! Sketch me! http://www.janewhitney.com/img/sister_chromatids.jpg

25. Mitosis • What it looks like: http://royaleb.files.wordpress.com/2009/04/mitosis_phases1.jpg

26. Mitosis • What it kinda looks like: http://www.geekosystem.com/wp-content/uploads/2010/07/donut-mitosis.jpeg

27. Mitosis • What it does not look like: http://icanhascheezburger.files.wordpress.com/2008/03/funny-pictures-mitosis-rabbits.jpg

28. The Steps of Mitosis • Prophase • Metaphase • Anaphase • Telophase • Cytokinesis • Got a way to remember these?

29. Wait just a second… • There’s a new organelle: the centriole. • Small barrel-shaped structure. • Comes from a region of the cytoplasm called the centrosome. • Produces spindle fibers. • Like ropes. • Not in most plant cells. http://staff.jccc.net/PDECELL/celldivision/images/metaphase.gif

30. http://student.ccbcmd.edu/courses/bio141/lecguide/unit6/genetics/DNA/DNArep/images/early_late_prophase1_pc.jpghttp://student.ccbcmd.edu/courses/bio141/lecguide/unit6/genetics/DNA/DNArep/images/early_late_prophase1_pc.jpg Prophase • Chromatin condenses into chromosomes. • Chromosomes have been copied by now and look like little X’s. • Nuclear membrane dissolves. • Spindle (the “ropes”) forms. http://img.sparknotes.com/figures/D/d756b5b73abe2974f3521a828791899f/prophase.gif

31. Prometaphase • Prometaphase is an intermediate step between Prophase and Metaphase (obvious). • YOU DO NOT NEED TO KNOW IT FOR MY CLASS, but in case you come across it elsewhere: • Starts when the nucleus breaks down and spindle fibers are forming. • Ends when the chromosomes are being moved into the center of the cell.

32. http://student.ccbcmd.edu/courses/bio141/lecguide/unit6/genetics/DNA/DNArep/images/metaphase1_ac.jpghttp://student.ccbcmd.edu/courses/bio141/lecguide/unit6/genetics/DNA/DNArep/images/metaphase1_ac.jpg Metaphase • Chromosomes line up in the middle of the cell. • Sometimes called the equator. • Spindle fibers attach (the ropes “hook on”) to the chromosomes at a site called the kinetochore (basically the centromere). http://img.sparknotes.com/figures/D/d756b5b73abe2974f3521a828791899f/metaphase.gif

33. http://student.ccbcmd.edu/courses/bio141/lecguide/unit6/genetics/DNA/DNArep/images/early_anaphase1_pc.jpghttp://student.ccbcmd.edu/courses/bio141/lecguide/unit6/genetics/DNA/DNArep/images/early_anaphase1_pc.jpg Anaphase • Centromeresdivide. • Sister chromatids pulled apart. • Chromatids move toward the poles. http://img.sparknotes.com/figures/D/d756b5b73abe2974f3521a828791899f/anaphase.gif

34. http://student.ccbcmd.edu/courses/bio141/lecguide/unit6/genetics/DNA/DNArep/images/telophase_ac.jpghttp://student.ccbcmd.edu/courses/bio141/lecguide/unit6/genetics/DNA/DNArep/images/telophase_ac.jpg Telophase • Nuclear envelope re-forms. • For just a little while, there are two nuclei. • Chromosomes decondense into chromatin. • Cytokinesisbegins. http://img.sparknotes.com/figures/D/d756b5b73abe2974f3521a828791899f/telophase.gif

35. http://www.bio.miami.edu/~cmallery/150/mitosis/sf8x9a.jpg Cytokinesis in Animal Cells • The cell divides. • Proteins pinch the membrane together between nuclei – forms a cleavage furrow. • Cell walls are a little different (next slide). http://img.sparknotes.com/figures/D/d756b5b73abe2974f3521a828791899f/cytokinesis.gif

36. http://wpcontent.answers.com/wikipedia/commons/thumb/5/5b/Phragmoplast.png/300px-Phragmoplast.pnghttp://wpcontent.answers.com/wikipedia/commons/thumb/5/5b/Phragmoplast.png/300px-Phragmoplast.png Cytokinesis in Plant Cells • Cell plate forms from vesicles (sent from Golgi). • Cell wall is inside the vesicle membrane. • Cell wall forms on top of the cell plate. http://student.ccbcmd.edu/courses/bio141/lecguide/unit6/genetics/DNA/DNArep/images/telophase2_pc.jpg

37. Mitosis Summary • This really cool company called Hybrid Medical Animations put together an awesome CGI look at mitosis in a cell. • http://www.hybridmedicalanimation.com/work/animation/the-stages-of-mitosis/ • While watching, write down ALL the cell organelles or structures you see. • I’ll be fishbowling the answers as we do some ListBuilding…

38. Summary of Mitosis Start with one diploid cell that has 46 chromosomes. 46 Mitosis 46 46 End with two cells called? They each have how many chromosomes? Two diploid daughter cells each with 46 chromosomes

39. Another Mitosis Summary…

40. Mitosis • What it actually really looks like (see the spindles?): http://www.geekosystem.com/wp-content/uploads/2010/07/donut-mitosis.jpeg

41. Mitosis Fun Facts • 300,000,000 cells die and are replaced every minute – roughly equal to the population of the United States. • 50,000,000 cells are born in the time it takes me to read this. • Nerve cells do not divide but are replaced from glial cells through neurogenesis.

42. Mitosis Rap • Yep, not kidding…we’re going to listen to a mitosis rap. • I didn’t do it…could you have guessed?

43. Mitosis Rap Lyrics “I” is for Interphase is step 1 the step before mitosis has begun “P” is for Prophase is step 2 the chromosome double dog that’s what they do. “M” is for Metaphase is step 3 the chromosomes line up as you can see. “A” is for Anaphase is step 4 as chromosomes move away from the core. “T” is for Telophase is step 5, right two daughter cells are made in both of our life…a’ight Mitosis tells all my cells to divide each cells put chromosomes to opposite sides It makes daughter cells that are two of a kind, two of a kind.

44. Other Mitosis Stuff • Mitosis App • https://itunes.apple.com/us/app/mitosis/id348184626?mt=8 • Mitosis – Phase Contrast Microscope

45. Cell Division Gizmo • Now, we’re going to put our knowledge to the test with a gizmo from ExploreLearning. • Called Cell Division Gizmo. • Directions are on the accompanying Quia quiz called Cell Division Gizmo. • [Log-in Instructions] • When you are done, attempt the Quia quiz called Labeling Mitosis. • This one’s important!

46. Exit Ticket • Exit Ticket: • Cells spend most of their time in which overallstage of the cell cycle? • Which stages does the cell enter when it is not in this phase? • What are the steps, in order, of mitosis?