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Explore the fascinating world of cells, from their structure and function to the revolutionary discoveries of early microscopists like Robert Hooke and Anton van Leeuwenhoek. Learn about the development of cell theory and the importance of microscopes in uncovering the secrets of the microscopic world. Discover how cells are the basic units of life and the building blocks of all living things.
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Chapter 2 Section 3 Discovering Cells Prokaryotic Cell
Key Terms • Cells • Microscope • Cell Theory Leaf under a microscope Microscope Infected red blood cells
Frog Blood Human Blood
An Overview of Cells • Cell- Basic units of life. • Cells and Structure • The structure of living things are determined by the amazing variety in which cells are put together. (LEGOS) • Cells and Function • An organisms function are the process that enable it to stay alive and reproduce. • Many and Small • One square centimeter of your skins surface contains more than 100,000 cells.
Development of Cell Theory • Cell Theory states the following: • All living things are composed of cells. • Cells are the basic units of structure and function in all living things. • All cells are produced from other cells. Cell Theory
First Observation of Cells Vocabulary: Microscope-An instrument that makes small objects look larger. • The invention of the microscope made it possible for people to discover and learn about cells. Blood under a microscope
Robert Hooke Robert Hooke was an English scientist who was one of the first to observe cells. In 1663, Hooke invented a microscope of his own, to observe the structure of a thin slice of cork. Anton van Leeuwenhoek Leeuwenhoek also began to observe tiny objects with microscopes at the same time as Robert Hooke. Leeuwenhoek looked at drops of lake water, and scraping of teeth and gums, and water from rain gutters. Microscopes 1663 microscope
http://www.youtube.com/watch?v=XgW1HiV9SJs&feature=player_detailpage#t=3http://www.youtube.com/watch?v=XgW1HiV9SJs&feature=player_detailpage#t=3
1590 first compound microscope Dutch eyeglass makers Zacharias and Hans Janssen made one of the first compound microscopes. 1981 scanning Tunneling Microscope An STM measures electrons that leak, or “tunnel,” from the surface of a specimen. STM’s can magnify a specimen up to 1 million times. Tech and Design in History Scanning Tunneling Microscope First compound microscope
Section 3 Assessment 1.a. Define function and structure. 1.b. Explain: Cells are the basic units of structure and function in organisms. 1.c. In what important function are the cells in your eyes involved? 2.a. What does a microscope enables people to do? 2.b. Summarize Hooke’s observation of cork under a microscope. 2.c. Why would Hooke’s discovery have been impossible without a microscope? 3.a. What are the main ideas of the cell theory? 3.b. What did Virchow contribute to the cell theory? 3.c. Use the ideas of Virchow to explain why plastic plants and stuffed animals are not alive. 4.a.What is magnification? 4.b.Contrast the way light microscopes and electron microscopes magnify objects.