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1.2.U4 ​Electron microscopes have a much higher resolution than light microscopes.

1.2.U4 ​Electron microscopes have a much higher resolution than light microscopes. Define resolution. Resolution is the the smallest interval distinguishable by the microscope, which then corresponds to the degree of detail visible in an image created by the instrument.

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1.2.U4 ​Electron microscopes have a much higher resolution than light microscopes.

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  1. 1.2.U4 ​Electron microscopes have a much higher resolution than light microscopes.

  2. Define resolution. Resolutionis the the smallest interval distinguishable by the microscope, which then corresponds to the degree of detail visible in an image created by the instrument. The magnification is the same, but the resolution is better with the electron microscope image.

  3. What can we see under a microscope?

  4. Compare the functionality of light and electron microscopes. LIGHT MICROSCOPES • Use lenses to bend light and magnify images • Used to study dead orliving cells in color • Cell movement can be studied • In IB Biology, you must be able to demonstrate use of a light microscope to: • Investigate the structure of cells • Identify phases of mitosis • Identify tissue layers of the small intestine ( • Draw xylem vessels in a stem cross section • Identify xylem and phloem in stem and root cross sections (

  5. Compare the functionality of light and electron microscopes. ELECTRON MICROSCOPES • Uses electron beams focused by electromagnets to magnify and resolve. • Requires cells to be killed and chemically treated before viewing, so no movement can be seen. • Without stain or dye, no color* can be seen. • The invention of the electron microscope led to greater understanding of cell structure. • In IB Biology, you’ll use electron microscope images to: • Draw prokaryotic and eukaryotic cells • Deduced functions of cells given structures visible in micrograph images • Understand evidence that led to the development of the fluid-mosaic model of membrane structure • Identify polysomes • Determine the contraction state of skeletal muscle fibers • Identify exocrine gland cells • Identify cells in lung tissue samples TEM: cross-sections of objects SEM: surface of objects * See the first color images produced by an electron microscope

  6. Compare the functionality of light and electron microscopes. ELECTRON MICROSCOPES • Smaller field of view • Can magnify objects up to 250,000 times. This is 125 times the magnifying power of light microscopes. • Can resolve objects that are 0.2 nm apart. This is 1000 times the resolving power of light microscopes. LIGHT MICROSCOPES • Larger field of view • Objects can be magnified up to 2000X. Ours at school only magnify 400X. • Can resolve objects 200 nm apart. This is 500 times better than the human eye.

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