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

2. 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

3. 2 Reasons why cells divide 2. _____________________ As cell grows bigger demand for transport across membrane is too great Material exchange can’t keep up http://www.animationlibrary.com

4. Ability to transport of oxygen, food, waste across cell membrane depends on _______________ Need for these depends on ___________ SURFACE AREA CELL VOLUME As cell grows these DON’T increase at the same rate

5. BIGGER CELLS NEED MORE FOOD and OXYGEN, but CAN’T TRANSPORT IT FAST ENOUGH or IN BIG ENOUGH QUANTITIES! http://www.animationlibrary.com

6. Multicellular organisms grow mainly by increasing cell number

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

8. DNA in PROKARYOTES BACTERIAL DNA is CIRCULAR NO NUCLEUS; ATTACHED TO CELL MEMBRANE http://www.origin-life.gr.jp/3202/3202121/fig6.jpg

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

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

11. ______________ = series of events that cells go through as they grow and develop CELL CYCLE

12. INTERPHASE – non-dividing phase G 1 - Grow bigger Cell is “doing its job” DNA is spread out as chromatin S - Synthesis (copy DNA) & chromosomal proteins G 2 - Grow bigger, make organelles & molecules needed for cell division

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

15. 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

16. PROPHASE 1st dividing phase Spindle fibers form & attach to chromosomes Nuclear membrane & nucleolus disappear DNA scrunches into chromosomes Centrioles appear in centrosome region & move to poles Pearson Education Inc publishing as Pearson Prentice Hall http://www.life.uiuc.edu/plantbio/102/lectures/08mit&veg102.html

17. ________ region organizes spindle Spindle MICROTUBULES are part of cytoskeleton http://www.coleharbourhigh.ednet.ns.ca/library/organelle_worksheet.htm CENTROSOME

18. METAPHASE Chromosomes line up in ___________ middle

19. ANAPHASE Centromeres split Centrioles pull chromatids_______ apart

20. TELOPHASE (reverse prophase steps) See ______ nuclei Nuclear membrane & nucleolus return Chromosomes spread out as chromatin Centrioles disappear Spindle fibers disappear two

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

22. 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