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Biology cell theory-and-and spontaneuous generation


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Biology cell theory-and-and spontaneous generation

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Biology cell theory-and-and spontaneuous generation

  2. 2. Early days <ul><li>1665 - Robert Hooke discovered and described the fundamental unit of all living things (cells) by examining thin slices of cork </li></ul><ul><li>He improved the first microscope </li></ul>
  3. 3. <ul><li>1674 - The first man to witness a live cell under a microscope was Anton Van Leeuwenhoek, describing the algae Spirogyra and named the moving organisms animalcules, meaning &quot;little animals&quot; </li></ul><ul><li>He is known as the “Father” of microscope </li></ul>Early days
  4. 4. <ul><li>1838 – Matthias Schleiden suggested that all plants are made of cells. </li></ul><ul><li>1839 – Theodor Schwann suggested that all animals are made of cells. </li></ul><ul><li>1855 – Rudolph Virchow’s theory: “all cells arise from pre-existing cells by cell division” </li></ul>CONTRIBUTORS TO THE CELL THEORY
  5. 5. General CELL THEORY emerged: “ the basic unit structure and function of all living organisms is the cell” CELL THEORY CELL THEORY CELL THEORY
  6. 6. Cell Theory <ul><li>All living things are composed of cells. </li></ul><ul><li>Cells are the basic unit of structure and function in living things. </li></ul><ul><li>All cells are produced from other cells. </li></ul>
  7. 7. SPONTANEOUS GENERATION <ul><li>At first scientists believed that living things came from non living things. </li></ul><ul><li>This theory was called spontaneous generation ( Abiogenesis) . </li></ul><ul><li>Scientists: </li></ul><ul><li>Francisco Redi </li></ul><ul><li>John Needham </li></ul><ul><li>Lazzaro Spallanzani </li></ul><ul><li>Louis Pasteur(disproved it) </li></ul>
  8. 8. Experiments on Spontaneous Generation (Abiogenesis) <ul><li>1668—Francisco Redi proposed the hypothesis that flies laying eggs on meat were responsible for the appearance of maggots. </li></ul><ul><li>If flies are prevented from laying their eggs on meat, then no maggots will appear on the meat. </li></ul>
  9. 9. HYPOTHESIS: Flies produce maggots . PROCEDURE Controlled Variables: jars, type of meat, location, temperature, time Manipulated Variables: gauze covering that keeps flies away from meat Uncovered jars Covered jars Several days pass Maggots appear No maggots appear Responding Variable: whether maggots appear CONCLUSION: Maggots form only when flies come in contact with meat. Spontaneous generation of maggots did not occur. Figure 1-8 Redi’s Experiment on Spontaneous Generation
  10. 10. Experiments on Spontaneous Generation <ul><li>mid-1700s— John Needham attacked Redi’s work. He claimed spontaneous generation could occur under the right conditions. He sealed a bottle of gravy and heated it. Several days later it was full of microorganisms (little animals). </li></ul><ul><li>Lazzaro Spallanzani read about Redi and Needham’s work and decided to improve on Needham’s experiment. </li></ul>
  11. 11. Gravy is boiled. Flask is open. Gravy is teeming with microorganisms . Gravy is boiled . Flask is sealed. Gravy is free of microorganisms . Section 1-2 Figure 1-10 Spallanzani’s Experiment Go to Section:
  12. 12. Experiments on Spontaneous Generation <ul><li>1800s—some scientists continued to support spontaneous generation. They thought that air was need to generate life because it contained some “life force” or “vital force.” </li></ul><ul><li>They said that Needham prevented air from reaching the broth. </li></ul><ul><li>1864— Louis Pasteur found a way to settle the argument with his “swan-neck flasks.” </li></ul>
  13. 13. <ul><li>Then in the mid 1800’s a man named Pasteur disproved this theory and it was replaced with a stronger theory called biogenesis , which states that all living things can only come from other living things. (Support Cell theory) </li></ul>SPONTANEOUS GENERATION
  14. 14. Figure 26.9 Louis Pasteur
  15. 15. Figure 26.9 Pasteur and biogenesis of microorganisms (Layer 1)
  16. 16. Figure 26.9 Pasteur and biogenesis of microorganisms (Layer 2)
  17. 17. Figure 26.9 Pasteur and biogenesis of microorganisms (Layer 3)
  18. 18. The Impact of Pasteur’s Work <ul><li>Saved the French wine industry </li></ul><ul><li>Saved the silk industry </li></ul><ul><li>Showed infectious diseases were caused by microorganisms </li></ul><ul><li>Developed vaccines against many diseases including anthrax and rabies </li></ul>
  19. 19. Experiments on Spontaneous Generation
  20. 20. Make a flip flap booklet on Spontaneous Generation Spontaneous Generation Francisco Redi’s Experiment Pg. 9 Draw and explain his experiment Lazzaro Spallanzani Pg. 11 All Facts know about the topic Pg 8 What is it? Louis Pasteur (Pg. 12)
  21. 21. Cytoplasm
  22. 22. Ans. The cell structure and function <ul><li>Cytoplasm </li></ul><ul><li>Mitochondria </li></ul><ul><li>ATP </li></ul><ul><li>Muscle and liver 2 </li></ul><ul><li>Crytal </li></ul><ul><li>Cristae </li></ul><ul><li>They enlarge the surface area for more </li></ul><ul><li>Reproduction </li></ul><ul><li>Ribosome </li></ul><ul><li>Membrane </li></ul><ul><li>Proteins </li></ul><ul><li>Cytosol </li></ul><ul><li>Endoplasmic rediculum </li></ul><ul><li>Protein </li></ul><ul><li>Produced </li></ul>Endoplasmic Reticulum (ER) Hyghway Rought and smooth Ribosome Protein steroids
  23. 23. Ans. <ul><li>Fedex, DHL </li></ul><ul><li>Lysosome </li></ul><ul><li>Animal </li></ul><ul><li>Cytoskeloeton </li></ul><ul><li>Shape and size </li></ul><ul><li>Membrane </li></ul><ul><li>Microfilament & microtubule </li></ul><ul><li>Spindel fiber </li></ul><ul><li>Cilial and Flagella </li></ul><ul><li>Movement </li></ul><ul><li>Nucleus </li></ul><ul><li>Nuclear envelop </li></ul><ul><li>DNE and protein </li></ul><ul><li>Heridity </li></ul>Nucleus Nuclear envelop DNE and protein Heridity Nuleoulus Ribosome
  24. 26. ANIMAL CELL
  25. 27. PLANT CELL
  26. 33. The Human Cheek Cell
  27. 34. The Human Cheek Cell <ul><li>Materials </li></ul><ul><li>Microscope </li></ul><ul><li>Methylene blue </li></ul><ul><li>Toothpick </li></ul><ul><li>Slide </li></ul><ul><li>Cover slide </li></ul>
  28. 35. The Human Cheek Cell Procedure <ul><li>1. Put a drop of methylene blue on a slide. Caution: methylene blue will stain clothes and skin. </li></ul><ul><li>2. Gently scrape the inside of your cheek with the flat side of a toothpick. Scrape lightly. </li></ul><ul><li>3. Stir the end of the toothpick into the stain and throw the toothpick away. </li></ul><ul><li>4. Place a cover slip onto the slide </li></ul><ul><li>5. Use the SCANNING objective to focus. You probably will not see the cells at this power. </li></ul><ul><li>6. Switch to low power. Cells should be visible, but they will be small and look like nearly clear purplish blobs. If you are looking at something dark purple, it is probably not a cell </li></ul><ul><li>7. Once you think you have located a cell, switch to high power and refocus.(Remember, do NOT use the coarse adjustment knob at this point) </li></ul>
  29. 36. The Human Cheek Cell Low High Sketch Scanning --- Sketch the cell at low and high power. Label the nucleus , cytoplasm , and cell membrane . Draw your cells to scale.
  30. 37. The Human Cheek Cell Questions <ul><li>1.  This cell is which cell type? </li></ul><ul><li>A. animal B. plant C. prokaryotic </li></ul><ul><li>2.  The shape of this cell, overall, is: </li></ul><ul><li>A. round B. rectangular C. other </li></ul><ul><li>3. What stain did you use to see this cell type? </li></ul><ul><li>4. What material does this particular stain reveal? </li></ul><ul><li>5.  Which organelles were apparent in this cell? </li></ul><ul><li>A. nucleus B. chloroplast C. central vacuole </li></ul><ul><li>6. Which cells are larger? </li></ul><ul><li>A. cheek B. bacteria </li></ul><ul><li>7. Is the cheek cell a eukaryote or prokaryote? How do you know? </li></ul><ul><li>8. Cheek cells do not move on their own, so you will not find two organelles that function for cell movement. Name these organelles. </li></ul>
  31. 38. The Human Cheek Cell Questions <ul><li>1. Why is methylene blue necessary? </li></ul><ul><li>2. Cheek cells do not move on their own, so you will not find two organelles that function for cell movement. Name these organelles. </li></ul><ul><li>3. The light microscope used in the lab is not powerful enough to view other organelles in the cheek cell. What parts of the cell were visible? </li></ul><ul><li>4. List 2 organelles that were NOT visible but should have been in the cheek cell. </li></ul><ul><li>5. Is the cheek cell a eukaryote or prokaryote? How do you know </li></ul><ul><li>6. Keeping in mind that the mouth is the first site of chemical digestion in a human. Your saliva starts the process of breaking down the food you eat. Keeping this in mind, what organelle do you think would be numerous inside the cells of your mouth? </li></ul>