Chapter 3- Micro

Which type of stain is most useful in helping clinicians to decide which antibiotic to prescribe for a bacterial infection? A. negative stain B. simple stain C. Gram stain D. endospore stain E. flagella stain

Which of the following is NOT true regarding the acid-fast stain? A. It is used to identify members of the genus Mycobacterium. B. Acid-fast cells retain the primary dye after treatment with acid-alcohol. C. If cells are acid-fast, they are gram-negative. D. Acid-fast cells appear red in a completed acid-fast stain. E. Non-acid-fast microbes appear blue in a completed acid-fast stain.

Which of the following is NOT useful for observing living cells? A. phase-contrast microscope B. darkfield microscope C. scanning acoustic microscope D. scanning electron microscope E. brightfield microscope

Which of the following is NOT equal to 1 mm? A. 0.001 m B. 10 6 nm C. 0.1 cm D. 100 m E. 10-3 m

Which of the following places the steps in the correct sequence? 1-Staining 2-Making a smear 3-Fixing A. 1-2-3 B. 3-2-1 C. 2-3-1 D. 1-3-2 E. The order is unimportant.

Bacterial smears are fixed before staining to A. affix the cells to the slide. B. make their walls permeable. C. accept stain. D. make the cells visible.

Which of the following correctly traces the path of light through the compound microscope? A. light source; condenser; specimen; objective lens; ocular lens B. condenser; light source; specimen; ocular lens; objective lens C. light source; specimen; condenser; objective lens; ocular lens D. condenser; light source; specimen; objective lens; ocular lens E. light source; condenser; objective lens; specimen; ocular lens

Which microscope is most useful for visualizing a biofilm? A. compound light microscope B. phase-contrast microscope C. fluorescence microscope D. scanning acoustic microscope E. transmission electron microscope

Which microscope is used to observe a specimen that emits light when illuminated with an ultraviolet light? A. compound light microscope B. phase-contrast microscope C. darkfield microscope D. fluorescence microscope E. electron microscope

Which microscope achieves the highest magnification and greatest resolution? A. compound light microscope B. phase-contrast microscope C. darkfield microscope D. fluorescence microscope E. electron microscope

Which step in the Gram stain is the critical step in differentiating gram-positive cells from gram-negative cells? A. safranin B. alcohol-acetone C. iodine D. crystal violet

Which microscope uses two beams of light to produce a three-dimensional color image? Which microscope uses two beams of light to produce a three-dimensional color image? A. fluorescence microscope B. phase-contrast microscope C. darkfield microscope D. DIC microscope E. electron microscope

In microscopy, the term resolution A. refers to the ability to distinguish fine structure and detail in a specimen. B. is the same as the total magnification of a specimen. C. is improved when longer wavelengths of light are employed. D. is only observed in stained specimens. E. refers to magnification when using the electron microscope.

In Figure 3.1, line "c" points to the microscope's A. illuminator. B. condenser. C. ocular lens. D. objective lens.

Which microscope is most useful for visualizing a biofilm? A. compound light microscope B. phase-contrast microscope C. fluorescence microscope D. scanning acoustic microscope E. transmission electron microscope

The purpose of the ocular lens is to A. improve resolution. B. magnify the image from the objective lens. C. decrease the refractive index. D. increase the light. E. decrease the light.

The purpose of a mordant in the Gram stain is to A. remove the simple stain. B. make the bacterial cells larger. C. make the flagella visible. D. prevent the crystal violet from leaving the cells. E. make gram-negative cells visible.

Assume you stain Bacillus by applying malachite green with heat and then counterstaining with safranin. Through the microscope, the green structures are A. cell walls. B. capsules. C. endospores. D. flagella. E. The answer cannot be determined.

Which of the following places the steps of the Gram stain in the correct order? 1-Alcohol-acetone 2-Crystal violet 3-Safranin 4-Iodine A. 1-2-3-4 B. 2-1-4-3 C. 2-4-1-3 D. 4-3-2-1 E. 1-3-2-4

You are performing a Gram stain on gram-negative bacteria and you stop after the addition of the mordant. What is the appearance of the bacteria at this point? A. purple B. red C. colorless D. brown

This microscope produces an image of a light cell against a dark background; internal structures are NOT visible. A. compound light microscope B. phase-contrast microscope C. darkfield microscope D. fluorescence microscope E. electron microscope

Which microscope can be used to visualize DNA or botulinum toxin? A. compound light microscope B. phase-contrast microscope C. scanning tunneling microscope D. confocal microscope E. scanning electron microscope

In using this microscope, the observer does NOT look directly at an image through a lens. A. compound light microscope B. phase-contrast microscope C. darkfield microscope D. fluorescence microscope E. electron microscope

Which microscope is used to see intracellular detail in a living cell? A. fluorescence microscope B. two-photon microscope C. atomic force microscope D. transmission electron microscope E. brightfield microscope

The purpose of the ocular lens is to A. improve resolution. B. magnify the image from the objective lens. C. decrease the refractive index. D. increase the light. E. decrease the light.

What is the total magnification of a specimen viewed with a 10x ocular lens and a 45x objective lens? A. 4.5x B. 10x C. 45x D. 100x E. 450x

Which microscope is best used for observing the surfaces of intact cells and viruses? A. phase-contrast microscope B. darkfield microscope C. fluorescence microscope D. brightfield microscope E. scanning electron microscope

Which microscope is used to see internal structures of cells in a natural state? A. compound light microscope B. phase-contrast microscope C. darkfield microscope D. fluorescence microscope E. electron microscope

You are studying a cell structure that is approximately 100 nm in size. Which of the following provides the lowest magnification you can use to see this structure? A. brightfield microscope B. darkfield microscope C. transmission electron microscope D. phase-contrast microscope E. scanning electron microscope

Which microscope is used to observe viruses and the internal structure of thinly sectioned cells? A. transmission electron microscope B. darkfield microscope C. fluorescence microscope D. brightfield microscope E. scanning electron microscope

The negative stain is used to A. visualize endospores. B. determine Gram reaction. C. determine flagella arrangement. D. visualize capsules. E. determine cell size.

Which of the following pairs is mismatched? A. nigrosin - negative stain B. methylene blue - simple stain C. acidic dye - capsule stain D. basic dye - negative stain E. crystal violet - simple stain

Simple staining is often necessary to improve contrast in which microscope? A. compound light microscope B. phase-contrast microscope C. darkfield microscope D. fluorescence microscope E. electron microscope

Which of the following is NOT useful for observing living cells? A. phase-contrast microscope B. darkfield microscope C. scanning acoustic microscope D. scanning electron microscope E. brightfield microscope

The resolution of a microscope can be improved by changing the A. condenser. B. fine adjustment. C. wavelength of light. D. diaphragm. E. coarse adjustment.

Which microscope uses visible light? A. confocal microscope B. differential interference contrast microscope C. fluorescence microscope D. scanning acoustic microscope E. scanning electron microscope

A virus measures 100 nm in length. What is its length in m? A. 10 m B. 1 m C. .1 m D. 0.01 m E. 0.001 m

Which of the following pairs is mismatched? A. confocal microscope -produces a three-dimensional image B. darkfield microscope -uses visible light C. fluorescence microscope -uses a fluorescent light D. scanning electron microscope -produces a three-dimensional image E. scanning tunneling microscope -allows visualization of atoms

Which microscope is used to observe a specimen that emits light when illuminated with an ultraviolet light? A. compound light microscope B. phase-contrast microscope C. darkfield microscope D. fluorescence microscope E. electron microscope

You are performing a Gram stain on gram-negative bacteria and you stop after the decolorizer step. What is the appearance of the bacteria at this point? A. purple B. red C. colorless D. brown

You are performing a Gram stain on gram-positive bacteria and you stop after the addition of the counterstain. What is the appearance of the bacteria at this point? A. purple B. red C. colorless D. brown