1. www.free-ppt-templates.com Cell Growth & Division

2. www.free-ppt-templates.com Do now: Who has bigger cells?

3. www.free-ppt-templates.com Do Now: Which has larger cells, a mouse or an elephant?

4. www.free-ppt-templates.com CELLS ARE SMALL!

5. www.free-ppt-templates.com Why do we need to make more cells?

6. www.free-ppt-templates.com From One Cell to Many Sea Urchin Cell Division

7. www.free-ppt-templates.com Why do we need to make more cells?

8. www.free-ppt-templates.com Why are we one hundred trillion SMALL cells and not one hundred LARGE cells? 100,000,000,000,000 cells because.... 100,000,000,000,000 cells because....

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10. I. Why do Cells Divide?

11. www.free-ppt-templates.com – The larger a cell becomes, the more demands on its DNA – Better organization – Needs to move nutrients and wastes across the cell membrane quickly – If too big, cannot get nutrients fast enough

12. www.free-ppt-templates.com DNA is the cell’s “library” of information. DNA is the cell’s “library” of information. Imagine a very large city using one local library for all materials Imagine a very large city using one local library for all materials

13. www.free-ppt-templates.com A big bag is weaker, harder to find things Large cell, difficult to maneuver organelles

14. www.free-ppt-templates.com More volume = bigger need The larger the volume of the balloon, the weaker it is. The balloon skin stays the same.

15. www.free-ppt-templates.com B. What is Surface area? The total area of the surface The total area of the surface of a 3D object of a 3D object B. What is Surface area? The total area of the surface The total area of the surface of a 3D object of a 3D object *Large surface area SPEEDS UP the movement of materials* What is the surface area of this cube? 24 cm 2 2 cm

16. www.free-ppt-templates.com C. What is Volume? The amount of 3-D space that an object occupies, “capacity” *Large volume SLOWS down movement of materials* What is the VOLUME of the shape here? 200 cm 3 cm

17. www.free-ppt-templates.com As the length of cell increases, volume increases faster surface area (cm 3 compared to cm 2 ) HIGH ratio desired: quick movement of materials Ex: 6000/1 is better than 2/1 As the length of cell increases, volume increases faster surface area (cm 3 compared to cm 2 ) HIGH ratio desired: quick movement of materials Ex: 6000/1 is better than 2/1

18. www.free-ppt-templates.com It’s better to have lots of small cells instead of fewer instead of fewer large cells!

19. www.free-ppt-templates.com A. All genes located in DNA in nucleus of eukaryotic cell B. Chromosomes are condensed forms of DNA

20. www.free-ppt-templates.com C.Chromosome number is unique to every species Humans: 46 chr. Chimpanzees: 48 chr. Yeast: 32 chr. Adders-Tongue Fern: 1440 chr.!

21. www.free-ppt-templates.com How is DNA Packaged? How is DNA Packaged? Chromosome- when chromatin coils for Chromosome- when chromatin coils for Mitosis Mitosis

22. www.free-ppt-templates.com Copied during Interphase Interphase D.After duplication phase, each chromosome consists of two identical “sister” chromatids Chromatids attached at the centromere the centromere

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26. B. Chromosome # stays the same (Cells growths, doubles chromosomes, then splits, forming two daughter cells with original # of chromosomes) 46 chromosomes 46 chr A.

27. www.free-ppt-templates.com Intestinal lining- every 24 hours Intestinal lining- every 24 hours Skin Skin Blood cells/bone marrow- 120 days Blood cells/bone marrow- 120 days Liver- sometimes Liver- sometimes

28. www.free-ppt-templates.com Muscle Cells Muscle Cells Cardiac cells Cardiac cells Kidney Kidney Nerve cells Nerve cells

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30. A.Interphase: “I-ball” 90% of the time! Gap 0 “resting phase”, cell is not growing Gap 1 cell grows, doubles organelles Synthesis duplication of the DNA in the cell's chromosomes Gap 2 cell grows, microtubules assembled

31. www.free-ppt-templates.com C. Checkpoints i. G1 Checkpoint: DNA to be replicated is healthy; cell size ii. G2 Checkpoint: Checks that DNA that was replicated is healthy; rest of cell ready for division iii. M checkpoint: Chromosomes are properly attached to the spindle fibers.

32. www.free-ppt-templates.com What happens if the cell cannot pass through the checkpoint? A)Repair the damage OR B) Self-destruct: APOPTOSIS (Programmed Cell Death) There are proteins in the cell that regulate these processes and determine which way the cell will go.

33. www.free-ppt-templates.com Prophase- “pasta” Chromatin fibers condense Nuclear membrane breaks down Spindle of microtubules forms from centrioles [animals only] Attach to chromatids on centromere

34. www.free-ppt-templates.com Metaphase- “middle” Chromosomes line up in the middle Spindle fibers attach centrioles to centromeres Every sister chromatid has fiber attached to it Centriole Spindle

35. www.free-ppt-templates.com Anaphase: “away phase”, form “A’s” Spindle fibers contract Pull sister chromatids apart The chromosomes continue to move until they are in two groups Each side has own copy of DNA Individualchromosomes

36. www.free-ppt-templates.com Telophase- “end phase” Nuclear membranes reform at each pole Chromosomes unwind Spindle disappears

37. www.free-ppt-templates.com D. CYTOKINESIS During cytokinesis, the cytoplasm cuts in half

38. www.free-ppt-templates.com A structure known as the CELL PLATE forms midway between the divided nuclei.

39. www.free-ppt-templates.com Animal cells contract across middle of cell and “pinch” making a “cleavage furrow”.

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42. Twilight STUDIES IT TOO!

43. www.free-ppt-templates.com MITOSIS MITOSIS Video Parent Cell Daughter Cells

44. www.free-ppt-templates.com A. Spindle: network of microtubules that move chromosomes during mitosis and meiosis B. Equator: center line of cell where chromosomes line up during metaphase C. Poles: the opposite ends of cell D. Centrioles: animal cells only, move the spindle and chromosomes during division

45. www.free-ppt-templates.com E. Centromere: region where two sister chromatids are joined tightly together

46. www.free-ppt-templates.com A. Production of 2 new daughter cells B. Daughter cells are exactly the same as original parent cell C. Cell --> Tissue --> Organ --> Organ System --> Organism D. This is how organisms grow & repair!