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What did Chapter 1 compare and contrast?
What did Chapter 1 compare and contrast?
Who discovered microorganisms?
Who discovered microorganisms?
What was of foremost importance in the development of microbiology?
What was of foremost importance in the development of microbiology?
What did microbiology become only after the development of appropriate instruments and techniques?
What did microbiology become only after the development of appropriate instruments and techniques?
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What kind of image does a compound light microscope form in the ocular diaphragm?
What kind of image does a compound light microscope form in the ocular diaphragm?
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What is used to increase resolution in a compound light microscope?
What is used to increase resolution in a compound light microscope?
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What is the purpose of immersion oils of high refractive index in a compound light microscope?
What is the purpose of immersion oils of high refractive index in a compound light microscope?
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What is the theoretical maximum resolving power for a compound light microscope?
What is the theoretical maximum resolving power for a compound light microscope?
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What kind of aberrations did early compound microscopes suffer from?
What kind of aberrations did early compound microscopes suffer from?
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What are prokaryotic cells almost invisible when viewed with?
What are prokaryotic cells almost invisible when viewed with?
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What are microorganisms often stained with to increase contrast between the cells and their environment?
What are microorganisms often stained with to increase contrast between the cells and their environment?
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Who perfected the compound light microscope in the late 19th century?
Who perfected the compound light microscope in the late 19th century?
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What are most dyes used to stain microorganisms?
What are most dyes used to stain microorganisms?
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What allows for increased resolution in the compound light microscope?
What allows for increased resolution in the compound light microscope?
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What kind of microscopes are used for observing internal cell structures?
What kind of microscopes are used for observing internal cell structures?
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What is used to correct lens aberrations in compound microscopes?
What is used to correct lens aberrations in compound microscopes?
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What is the typical near point of the human eye for adults?
What is the typical near point of the human eye for adults?
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What type of microorganisms have a cell diameter of only 0.001 mm?
What type of microorganisms have a cell diameter of only 0.001 mm?
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Who is credited with constructing simple microscopes that could magnify 200-300-fold?
Who is credited with constructing simple microscopes that could magnify 200-300-fold?
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What type of microscopes use two lenses (objective and eyepiece) to magnify specimens?
What type of microscopes use two lenses (objective and eyepiece) to magnify specimens?
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What is the overall magnification when using a 60× objective lens and a 10× eyepiece?
What is the overall magnification when using a 60× objective lens and a 10× eyepiece?
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What is used to provide high-intensity light and control brightness in compound microscopes?
What is used to provide high-intensity light and control brightness in compound microscopes?
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What is the useful magnification maximum of a light microscope?
What is the useful magnification maximum of a light microscope?
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What does the resolving power of an optical system define?
What does the resolving power of an optical system define?
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What does the resolving power equation include?
What does the resolving power equation include?
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What does a lower value of resolving power indicate about the optical system?
What does a lower value of resolving power indicate about the optical system?
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What does improving image formation in light microscopy involve?
What does improving image formation in light microscopy involve?
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Which type of stain is useful in staining positively charged cell components such as protein?
Which type of stain is useful in staining positively charged cell components such as protein?
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What type of microscopy produces a bright image against a dark background, allowing the observation of living cells?
What type of microscopy produces a bright image against a dark background, allowing the observation of living cells?
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Which microscopy technique amplifies the slight difference in refractive index between microbial cells and their aqueous environment to enhance contrast?
Which microscopy technique amplifies the slight difference in refractive index between microbial cells and their aqueous environment to enhance contrast?
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Which type of bacteria retain the color of a dye when rinsed in a solution of ethanol containing hydrochloric acid?
Which type of bacteria retain the color of a dye when rinsed in a solution of ethanol containing hydrochloric acid?
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Which type of stain is used to distinguish between gram-positive and gram-negative bacteria?
Which type of stain is used to distinguish between gram-positive and gram-negative bacteria?
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What type of microscopy is advantageous for specifically staining nucleic acid components of cells?
What type of microscopy is advantageous for specifically staining nucleic acid components of cells?
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What is the main purpose of simple stains in microscopy?
What is the main purpose of simple stains in microscopy?
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Which type of microscopy allows the observation of cells on opaque surfaces?
Which type of microscopy allows the observation of cells on opaque surfaces?
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What is the primary characteristic of basic dyes used for staining microorganisms?
What is the primary characteristic of basic dyes used for staining microorganisms?
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What is the distinguishing feature of acid-fast bacteria?
What is the distinguishing feature of acid-fast bacteria?
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Which type of stain is effective for staining microorganisms with a near-neutral internal pH and negatively charged cell surface?
Which type of stain is effective for staining microorganisms with a near-neutral internal pH and negatively charged cell surface?
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What is the main advantage of wet-mount preparations in darkfield microscopy?
What is the main advantage of wet-mount preparations in darkfield microscopy?
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Which microscopy technique uses a laser beam to illuminate and view microorganisms in three-dimensional space?
Which microscopy technique uses a laser beam to illuminate and view microorganisms in three-dimensional space?
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What is the illuminating source used in transmission electron microscopy (TEM)?
What is the illuminating source used in transmission electron microscopy (TEM)?
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Why is TEM not suitable for observing living cells?
Why is TEM not suitable for observing living cells?
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What is used to focus the electron beam in transmission electron microscopy?
What is used to focus the electron beam in transmission electron microscopy?
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What is the major application of TEM in biology?
What is the major application of TEM in biology?
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What type of light is used for incident illumination in fluorescence microscopes?
What type of light is used for incident illumination in fluorescence microscopes?
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What type of light is emitted by fluorescent dyes in fluorescence microscopes?
What type of light is emitted by fluorescent dyes in fluorescence microscopes?
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What is the theoretical resolution achieved by transmission electron microscopy (TEM)?
What is the theoretical resolution achieved by transmission electron microscopy (TEM)?
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What is used to replace optical lenses in TEM?
What is used to replace optical lenses in TEM?
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What is the purpose of heavy metal stains like phosphotungstic acid or uranyl acetate in TEM?
What is the purpose of heavy metal stains like phosphotungstic acid or uranyl acetate in TEM?
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What type of images do electron micrographs in TEM provide compared to light microscopes?
What type of images do electron micrographs in TEM provide compared to light microscopes?
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What is the illuminating source used in epifluorescence scanning microscopy?
What is the illuminating source used in epifluorescence scanning microscopy?
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Study Notes
Microscopy Techniques in Microbiology
- Fluorescence microscopes use short-wavelength light from mercury or halogen lamps for incident illumination and view longer-wavelength light emitted by fluorescent dyes.
- Confocal scanning microscopes use a laser beam to illuminate and view microorganisms in three-dimensional space, providing images free from diffracted light.
- Epifluorescence scanning microscopy uses a laser beam to illuminate and view a cross-section of the specimen stained with a fluorescent dye.
- The transmission electron microscope (TEM) utilizes electrons as the illuminating source, achieving a theoretical resolution of about 2 Å, twice the diameter of a hydrogen atom.
- TEM uses electromagnetic lenses to focus the electron beam and requires a vacuum to permit the flow of electrons through the lens system.
- The real image in TEM is formed by electrons bombarding a phosphorescent screen, and the photograph is taken by a camera mounted below the screen.
- TEM is not suitable for observing living cells due to the vacuum chamber requirement and uses thin sectioning to observe internal cell structures.
- Electron micrographs in TEM provide increased detail compared to light microscopes, even at similar magnifications.
- Cell preparations for TEM are placed on a small grid and stained with heavy metal stains like phosphotungstic acid or uranyl acetate.
- The major application of TEM in biology is to observe internal cell structures, requiring a more elaborate procedure called thin sectioning.
- TEM has a larger size than the ordinary light microscope due to the vacuum chamber and use of electron magnets for lenses.
- Unlike light microscopes, TEM images are formed using electrons as the illuminating source and magnets to replace optical lenses.
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Description
Test your knowledge of microscopy techniques in microbiology with this quiz. Explore fluorescence microscopy, confocal scanning microscopy, and transmission electron microscopy (TEM), including their principles, applications, and differences from light microscopes.
