1. CELL GROWTH & DIVISION 10-1 & 10-2

2. Pre-assessment Quiz Cell Growth and Division

3. Limits to Cell Growth 1.DNA “Overload” 2.Exchanging Materials 3.Ratio of Surface Area to Volume 4.Cell Division

4. 2 Reasons why cells divide 1. _____________________ As cell grows bigger demand on DNA “genetic library” becomes too great Ex: Small town library has 1000 books. As town grows and more people borrow books, there may be a waiting list to read the most popular titles DNA OVERLOAD http://www.adc.state.az.us/images/Off-Library.JPG

5. 2 Reasons why cells divide 2. _____________________ As cell grows bigger, it gets harder to transport “stuff” across membranes Material exchange can’t keep up http://www.animationlibrary.com

6. The ability to transport of oxygen, food, waste across cell membrane depends on _______________ How much of this “stuff” used depends on ___________ SURFACE AREA CELL VOLUME As cell grows these DON’T increase at the same rate, volume increases faster than surface area

7. When cells get too big, they can’t transport “stuff” fast enough, or in big enough amounts. http://www.animationlibrary.com So cells grow by dividing into many, small cells instead of growing few, bigger cells.

8. 10–2Cell Division A. Chromosomes B. The Cell Cycle C. Events of the Cell Cycle D. Mitosis 1.Prophase 2.Metaphase 3.Anaphase 4.Telophase E. Cytokinesis

9. SPREAD OUT IN NON-DIVIDING CELLS SCRUNCHED UP IN DIVIDING CELLS CHROMATIN CHROMOSOMES DNA CAN BE:

10. DNA in PROKARYOTES (Bacteria) BACTERIAL DNA is CIRCULAR HAVE ONE CHROMOSOME NO NUCLEUS; ATTACHED TO CELL MEMBRANE

11. DNA in EUKARYOTES (Plants & Animals) DNA is ROD-SHAPED CHROMOSOMES MANY PAIRS FOUND IN NUCLEUS http://cellbio.utmb.edu/cellbio/chrom2.jpg

12. All organisms have specific numbers of chromosomes Humans = _____ Chromosomes Fruit Flies = 8 Chromosomes Carrots = 18 Chromosomes Chromosomes (scrunched up DNA) 46

13. Chromosome structure ___________________ 2 identical arms __________________ area that holds the chromatids together __________________ PAIR A pair of chromosomes (2) (one from mom; one from dad) CHROMATIDS CENTROMERE HOMOLOGOUS

14. HOMOLOGOUS CHROMOSOMES http://arnica.csustan.edu/biol3020/cell_division/cell_division.htm SAME SIZE SAME SHAPE CARRY GENES for the SAME TRAITS BUT _________________! Both have the same gene, but they don’t have to be the same trait expressed Ex. Eye color might not have the same color of eyes http://sps.k12.ar.us/massengale/genetics%20tutorial.htm NOT IDENTICAL

15. CELL DIVISION in PROKARYOTES Bacteria reproduce using __________________________________ BINARY FISSION http://fig.cox.miami.edu/~cmallery/150/mitosis/fission.jpg

16. Cell Cycle Interphase G 1 S G 2 Mitosis (M) phase Prophase Metaphase Anaphase Telophase Cytokinesis

17. CELL CYCLE – “in between” division G 1 - Gap phase 1, Cell Growth Cell Growth, increase size Cell is “doing its job” DNA is spread out as chromatin S – Synthesis phase Chromosomes are copied G 2 - Gap phase 2, Prepare for Mitosis Cell growth, get ready for cell division by producing organelles & molecules INTERPHASE

18. CELL DIVISION – Nucleus divides Prophase Metaphase Anaphase Telophase Cytokinesis – Cytoplasm divides G 0 – cell stops dividing (Ex: nerve cell) MITOSIS

19. INTERPHASE (G 1 - S - G 2 ) In between divisions Cells are in this phase most of the time Can see nucleus DNA spread out as chromatin Can’t see chromosomes DNA gets copied (S) Cell gets ready to divide

20. PROPHASE 1st dividing phase Chromosomes appear (scrunched up X shape) Centrioles appear in & move to opposite poles of the nucleus Spindle fibers form & attach to chromosomes to help them separate Nuclear membrane & nucleolus disappear Pearson Education Inc publishing as Pearson Prentice Hall http://www.microscopy.fsu.edu/micro/gallery/mitosis/mitosis.html

21. METAPHASE Chromosomes line up in ___________ middle Images from: Pearson Eduction Ince; Publishing as Pearson Prentice Hall http://www.microscopy.fsu.edu/micro/gallery/mitosis/mitosis.html Microtubules connect the centromere to the two poles of the spindle

22. ANAPHASE Centromeres split and the centrioles pull the two sister chromatids _______ Anaphase ends when the movement stops apart Images from: Pearson Eduction Ince; Publishing as Pearson Prentice Hall http://www.microscopy.fsu.edu/micro/gallery/mitosis/mitosis.html

23. TELOPHASE See ______ nuclei Nuclear envelope & nucleolus return Chromosomes spread back out as chromatin Centrioles disappear Spindle fibers break and disappear two Images from: Pearson Eduction Ince; Publishing as Pearson Prentice Hall http://www2.bc.cc.ca.us/cnewton/Biology%2011/Mitosis.html

24. CYTOKINESIS Cytoplasm splits into 2 cells ANIMAL CELLS pinch cytoplasm in two with a ______________________ CLEAVAGE FURROW

25. CYTOKINESIS Cytoplasm splits into 2 cells PLANT CELLS can’t pinch because they have a sturdy ____________ Plant cells separate cytoplasm by growing a _______________ down the middle. CELL PLATE CELL WALL http://www.eastcentral.edu/acad/depts/BI/plant_mitosis_nolabels.html

26. Cell Cycle Video http://www.cellsalive.com/mitosis.htm http://sciencevideos.wordpress.com/2007/09/ 24/the-cell-cycle-mitosis/ http://sciencevideos.wordpress.com/2007/09/ 24/the-cell-cycle-mitosis/ Animation 2: http://science.education.nih.gov/supplements/ nih1/cancer/activities/activity2_animations.ht m http://science.education.nih.gov/supplements/ nih1/cancer/activities/activity2_animations.ht m

28. includes is divided into Concept Map Section 10-2 Cell Cycle

29. includes is divided into Concept Map Section 10-2 Cell Cycle M phase (Mitosis) Interphase G 1 phaseS phaseProphaseG 2 phaseMetaphaseTelophaseAnaphase

31. REGULATING the CELL CYCLE

32. Regulating the Cell Cycle Controls on Cell Division Cell Cycle Regulators 1.Internal Regulators 2.External Regulators Uncontrolled Cell Growth

33. Controls of Cell Division Cells in a petri dish will continue to grow until they touch other cells. Cells in our bodies will do the same thing. Ex. A finger that stops bleeding.

34. CELL DIVISION GENES Some cells divide frequently (some human skin cells divide once/hour) Some cells divide occasionally (liver cells divide about once/year) Some cells don’t divide once they form (nerve cells)

35. In early 1980’s scientists discovered a protein in dividing cells that caused a ______________to form in _______________ cells CELL CYCLE REGULATORS Mitotic spindle NON-dividing Pearson Education Inc; Publishing as Pearson Prentice Hall

36. Levels of this protein rose and fell with the cell cycle so it was named __________ because it seemed to control the cell cycle. A whole family of CYCLINS have since been discovered that regulate the _____________________ in EUKARYOTIC CELLS CELL CYCLE REGULATORS CYCLIN TIMING of CELL CYCLE Pearson Education Inc; Publishing as Pearson Prentice Hall

37. ______________ REGULATORS Proteins that respond to events inside the cell. They allow cell cycle to proceed only if certain processes have happened EX: Cell can’t enter mitosis until all the chromosomes have been copied OTHER REGULATORS INTERNAL

38. ______________ REGULATORS Proteins that respond to events outside the cell. Signals tell cell to speed up or slow down the cell cycle EX: Growth factors stimulate cells to divide. Especially important during wound healing and embryo development OTHER REGULATORS EXTERNAL http://www.suite101.com/files/topics/6234/files/tail_HumanTail.gif

39. Molecules on the surface of neighboring cells act as signals to slow down or stop the cell’s cycle. These signals prevent excessive growth and keep tissues from disrupting each other. EXTERNAL REGULATORS Pearson Education Inc; Publishing as Pearson Prentice Hall

40. Cancer cells have lost control of their cell division genes – they don’t stop growing when they touch nearby cells... they just keep growing! That’s what makes a tumor. NO CONTACT INHIBITION http://www.exn.ca/news/images/2000/08/02/20000802-cancer.jpg

41. Cancer cells Don’t stop dividing Like a “car with no brakes” Can spread to new places by entering the bloodstream (METASTASIS) ______________ are substances that can damage DNA and cause cancer Ex: Cigarette smoke (OR CHEW), Radiation, chemicals in environment, even viruses, Carcinogens http://www.dfci.harvard.edu/abo/news/publications/pop/fall-winter-2004/images/metastasis_1.jpg

42. Cancer cells Cancer is complicated and can have many causes, but all cancers have one thing in common. They have lost control over their _____________. Many cancers cells have a damaged or defective gene called _____, so they can’t respond to normal cell signals to control their growth. CELL CYCLE p53

43. Cancer

44. Animation 1: http://science.education.nih.gov/supplements/ni h1/cancer/activities/activity2_animations.htm http://science.education.nih.gov/supplements/ni h1/cancer/activities/activity2_animations.htm

45. ANTI-SMOKING commercial