MicroBio Chapter 4 Self Test

A fluorescent dye absorbs the energy from ______ and emits light in the visible spectrum. a. an electron beam b. another fluorescent dye c. ultraviolet light d. phalloidin e. fluorescein

a.

A(n) ______ microscope is a variation of a fluorescence microscope that uses point illumination and scanning to produce a three-dimensional image. a. scanning electron b. scanning tunneling c. atomic force d. differential interference contrast e. confocal

a.

In which type of microscope does the specimen appear against a black background because of light being reflected off the surface of the specimen into the objective lens? a. differential interference microscope b. confocal microscope c. dark-field microscope d. super-resolution microscope e. bright-field microscope

a.

Scanning tunneling microscopy and atomic force microscopy are fundamentally different from other types of microscopy because they ______. a. use a nanoprobe that scans the surface of the specimen to produce an image b. use a scattered electron beam to produce an image c. assemble an image from light defracted off the surface of the specimen by prisms d. only work on living specimens e. Both b and d are correct.

a.

Staining procedures that use multiple dyes are called ______. a. simple staining b. negative staining c. differential staining d. acidic staining e. mordant staining

a.

As resolution ______ the clarity of the image ______. a. increases; increases b. decreases; decreases c. decreases; increases d. decreases; stays the same e. increases; stays the same

a. increases; increases

Light is ______ when it passes from one medium to another with a different optical density. a. refracted b. resolved c. magnified d. focused e. Both b and d are correct.

a. refracted

A transmission electron microscope uses ______ for lenses and a(n) ______ to magnify the image. a. electromagnets; nanoprobe b. glass; nanoprobe c. electromagnets; electron beam d. glass; electron beam e. electron beams; electromagnets

c.

In the diagram, the light entering the oil ______. a. is bent more than the light passing through air b. is reflected back toward the source c. is not refracted d. cannot pass through it e. is reflected and refracted

c.

Review What a Microbiologist Sees, and answer this question.The three-dimensional aspect of the Stentor image is created by ______. a. the use of dyes b. changes in the phases of light as it passes through the specimen c. coating of the specimen with metals d. the type of glass in the eyepiece of the microscope e. the large size of the specimen

c.

Review the Clinical Application, and answer this question.Tuberculosis is caused by Mycobacterium tuberculosis, a(n) ______ bacterium. a. non-acid-fast b. gram-positive c. gram-variable d. gram-negative e. acid-fast

c.

Review the Process Diagram, Figure 4.6, and answer this question.Place the listed chemicals in the correct order for Gram staining: safranin, iodine, ethanol, crystal violet a. crystal violet, safranin, ethanol, iodine b. iodine, safranin, ethanol, crystal violet c. iodine, crystal violet, safranin, ethanol d. crystal violet, iodine, ethanol, safranin e. crystal violet, iodine, safranin, ethanol

c.

Image size divided by actual size is a measure of ______. a. resolution b. refractive index c. magnification d. numerical aperture e. focal length

c. Magnification

Review The Microbiologist's Toolbox, and answer this question.A positive test for a pathogen produced by a(n) ______ dye conjugated to a ______ shows as glowing spots when viewed with a(n) ______ microscope. a. acid; fluorescent antibody; dark-field b. basic; polyclonal antibody; bright-field c. neutral; fluorescent antibody; confocal d. fluorescent; monoclonal antibody; fluorescence e. acid; monoclonal antibody; electron

d.

The diagram depicts the structure of a ______. a. bright-field microscope b. dark-field microscope c. fluorescence microscope d. confocal microscope e. phase contrast microscope

d.

If a light microscope has a 10× ocular lens and a 40× objective lens, how large will the image of an amoeba 15 μm in diameter appear? a. 150 μm b. 600 μm c. 1.5 mm d. 6.0 mm e. 750 μm

d. 6.0 mm

Review the Microbiology InSight, Figure 4.2, and answer this question. With a compound microscope, light intensity is controlled by adjusting the ______. a. condenser lens b. focus knob c. stage d. iris diaphragm e. ocular lens

d. iris diaphragm

The green-stained structures in the micrograph are ______. a. nuclei b. bacteria c. red blood cells d. endospores e. crystal violet

e.

The image in this photo was made by ______ that ______. a. an electron beam; passed through prisms b. an electron beam; passed through the specimen c. light; passed through prisms d. light; passed through the specimen e. an electron beam; scattered off the specimen surface

e.

Which microscope generates a three-dimensional image and converts differences in refractive indexes in a specimen to differences in color as the result of using prisms? a. phase contrast microscope b. differential interference contrast microscope c. confocal microscope d. dark-field microscope e. Both a and c are correct.

e.