1. Cell Division Mrs. Walker 7 th Grade Science

2. Bellwork 12/7/15 On Desk: -Planner -Pen/Pencil -IAN 1. Do you think you have the same amount of cells you did at birth? In 4-5 sentences explain why or why not.

3. Let’s Review Cells!  What do you know and remember about cells?  What are cells?  What is their function?  Cell  Cell theory  Prokaryote  Eukaryote  Organelle

4. What’s different about a cell and an atom?  Cell- basic unit of life.  You can’t be considered alive if you are not composed of cells.  Atoms – basic unit of matter, smallest part of an element  Atoms & Cells are two very different things.

5. What is The Cell Theory? 1. All living things are made up of cells. 2. Cells are the basic units of structure and function in living things. 3. New cells are produced from existing cells.

6. Remember these?

7. What does the Nucleus do?  Contains DNA. - DNA: contains the hereditary information.  Controls most cell processes. - Makes proteins…the building blocks of almost everything.

8. DNA forms in the Nucleus 1.Chromatin-  Consists of DNA bound to protein.  Spread throughout the nucleus, but during cell division it condenses to form… 2. Chromosomes-  Contain hereditary genetic information.

9. How do little elephants grow up to be BIG elephants?

10. Why do animals shed their skin?

11. Update your Table of Contents (Blank Left and Right hand Page) Title: Cell Division/Mitosis

12. Cell division  In multicellular organisms cell division is needed for three things:  Growth  Reproduction  Repair

13. Growth  Efficiency of moving materials into the cell  The larger the cell becomes the less efficient it is.  The volume of the cell increases faster than its surface area.  Cells that grow too large no longer have enough surface area to take in nutrients and remove waste.

14. Growth © Pearson Education, Inc. Cell Size Surface Area (length x width x 6) Volume (length x width x height) Ratio of Surface Area to Volume 1 cm x 1 cm x 6 = 6 cm 2 2 cm x 2 cm x 6 = 24 cm 2 3 cm x 3 cm x 6 = 54 cm 2 1 cm x 1 cm x 1 cm = 1 cm 3 2 cm x 2 cm x 2 cm = 8 cm 3 3 cm x 3 cm x 3 cm = 27 cm 3 6 / 1 = 6 : 1 24 / 8 = 3 : 1 54 / 27 = 2 : 1

15. Reproduction  Cells divide in order to reproduce themselves.  All cells come from preexisting cells.  Most cells divide by mitosis = making exact copies of themselves

16. Reproduction

17. Repair  Cells divide to repair tissues upon injury  Cells divide to replace old or damaged cells  When cell division goes wrong, cancer can occur

18. Repair

19. First, before a cell can split…  It must copy it’s genetic information.  Each daughter cell then gets a complete copy of that information.

20. How is genetic info passed on? o Chromosomes carry the cells coded genetic information. o Made up of DNA and proteins.  Human cells have 46 chromosomes.  23 pairs.  Organisms can have different #’s of chromosomes.

21. Before cell division… Each chromosome is replicated (copied)!

22. Mitosis Cycle Interphase Prophase Metaphase Anaphase Telophase Cytokinesis

23. Animated Mitosis Cycle Cell division occurs in a series of stages, or phases. http://www.cellsalive.com/mitosis.htm

24. Let’s Read About It!!!  Open your text to page 96.  Title It : Cell Division Reading -Page 96 Summarize: 1. Why is cell division important? 2. Each phase of Cell Division

25. Cells Packet  Due Friday

26. Bellwork 12/9/15 On Desk: -Planner -Pen/Pencil -IAN -Text Book 1. List the three reasons cells divide. Cells divide in order to grow, reproduce and repair themselves. 2. Is this a picture of Chromatin or a chromosome? How do you know? The DNA is condensed so it is a picture of two chromosomes.

27. Let’s Read About It (Continued)  Open your text to pages 96-99 2. Summarize each phase of Cell Division  Interphase  Prophase  Metaphase  Anaphase  Telophase  Cytokinesis

28. Mitosis Notes (Input Side) 1. Cut out each phase picture and description. (You will have 12 pieces of paper) 2. As we take notes, fill in the blanks and glue in both the phase picture and description.

29.  Phases of Mitosis  Interphase  Prophase  Metaphase  Anaphase  Telophase  Cytokinesis

30.  Interphase: occurs before mitosis begins  Chromosomes are copied (# doubles)  Chromosomes appear as threadlike coils ( chromatin ) at the start, but each chromosome and its copy change to sister chromatids at end of this phase CELL MEMBRANE Nucleus Cytoplasm

31. Animal Cell Plant Cell Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm

32.  Prophase: first step in mitosis  Centrioles (or poles) appear and begin to move to opposite ends of the cell.  Spindle fibers form between the poles. Centrioles Sister chromatids Spindle fibers

33. Animal Cell Plant Cell Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm Spindle fibers Centrioles

34.  Metaphase: 2 nd step in mitosis  Chromatids (or pairs of chromosomes) attach to the spindle fibers. Centrioles Spindle fibers

35. Animal Cell Plant Cell Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm

36.  Anaphase: 3 rd step in mitosis  Chromatids (or pairs of chromosomes) separate and begin to move to opposite ends of the cell. Centrioles Spindle fibers

37. Animal Cell Plant Cell Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm

38.  Telophase: 4 th step in mitosis  Two new nuclei form.  Chromosomes appear as chromatin (threads rather than rods).  Mitosis ends. Nuclei Chromatin

39. Animal Cell Plant Cell Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm

40.  Cytokinesis: occurs after mitosis  Cell membrane moves inward to create two daughter cells – each with its own nucleus with identical chromosomes.

41. Animal Mitosis -- Review Interphase Prophase Metaphase Anaphase Telophase Interphase

42. Plant Mitosis -- Review Interphase Prophase Metaphase Anaphase Telophase Interphase

43. I I nterphase P P rophase M M etaphase A A naphase T T elophase IPMAT

44.  https://www.pinterest.com/pin/33143747232645823/ https://www.pinterest.com/pin/33143747232645823/

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46. 46 - Cell Division 46

49. Bellwork Quiz 1. 9/15/15 #1 2. 11/2/15 #2 3. 11/9/15 #1 4. 11/13/15 #2 Use the following format to receive full credit. Q:_______________________ A:_______________________

50. Key 1.9/15/15 #1 What are the seven steps of the scientific method? 1.Choose problem 2.Research problem 3.Develop hypothesis 4.Write procedures 5.Test hypothesis 6.Organize data 7.State conclusions 2.11/2/15 # 2 What is the largest known cell? The largest know cell is the ostrich egg. 3. 11/9/15 #1 What is the difference between a prokaryote and a eukaryote? Prokaryotes lack internal structure whereas eukaryotes have several organelles. 4. 11/13/15 #2 What is the endoplasmic reticulum of your analogy and how does it function?