chapter 3

Acid-fast Mycobacteria differ from non-acid-fast bacteria by the presence of __________. A.)waxy material in their cell walls B.)flagella C.)endospores D.)capsules E.)peptidoglycan

A

A paramecium is approximately 150 micrometers in length. What is this measurement expressed in millimeters (mm)? A.) 1500 mm B.) 0.15 mm C.) 15 mm D.) 0.015 mm E.) 1.5 mm

B

Cells are differentiated after which step in the Gram stain? A) Safranin B) Alcohol-acetone C) Iodine D) Crystal violet

B

Chlamydia trachomatis elementary bodies measure approximately 0.25 micrometers in diameter. What is this measurement expressed in nanometers (nm)? A.) 2.5 nm B.) 250 nm C.) 2500 nm D.) 25,000 nm E.) 25 nm

B

Immersion oil is used with the 100 × objective lens of the compound light microscope to __________. A.)condense the light B.)prevent the loss of resolution due to refraction C.)separate the light into different wavelengths D.)increase contrast by bending light

B

A __________ is equal to 0.000001 m.

micrometer

• viewing the three-dimensional shape of a protozoan and the arrangement and distribution of cilia on its surface • determining the three-dimensional shape and arrangement of bacterial cells A.) light microscope B.) scanning electron microscope C.)transmission electron microscope

B

Which type of microscope uses a metal and diamond probe that is gently forced down along the surface of a specimen? A.)Scanning electron B.)Confocal C.)Scanning tunneling D.)Transmission electron E.)Atomic force

E

Which of the following staining procedures is matched with the principal use for that stain? A.) endospore stain to visualize structures which enable bacteria to move and swim B.) flagella stain used to distinguish dormant structures formed during adverse environmental conditions C.) negative stain used to differentiate cell wall components D.)acid-fast stain for microbes with waxy cell walls

D

A student is observing a Gram stain with the 100 × (oil immersion) lens. The image appears cloudy and dark. Which of the following actions will NOT increase the clarity of the image? A.)Adjusting the condenser to better focus light through the specimen B.)Increasing the light using the diaphragm C.)Lowering the stage to increase the distance between the object and the objective lens D.)Using lens paper to clean any dirt or old oil off the lenses

C

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) Canʹt tell.

C

In Figure 3.1 line A points to the microscopeʹs A) illuminator. B) condenser. C) ocular lens. D) objective lens.

C

In a typical brightfield microscope (seen in the animation), at which point does magnification begin? A.) The condenser lens B.)The stage C.) The objective lens D.)The lamp E.)The ocular lens

C

In the Gram stain, what is the purpose of the decolorizer? A.)To clean off excess stain B.)To stain gram-negative cells C.)To selectively remove stain from cells D.)To wash slides

C

Place the following 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 doesnʹt matter

C

Place 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

C

The __________ charge of a basic dye adheres to the __________ charge of bacterial cell surfaces. A.)negative; positive B.)negative; acidic C.)positive; negative D.)positive; acidic E.)positive; basic

C

The appearance of gram-negative bacteria after addition of the decolorizing agent in the Gram stain. A) Purple B) Red C) Colorless D) Brown E) None of the above

C

The counterstain in the Gram stain is A) A negative stain. B) A mordant. C) A basic dye. D) An acid dye. E) Necessary to determine the Gram reaction.

C

The light that hits the specimen is scattered and does not come directly from the light source in this microscope. A) Compound light microscope B) Phase-contrast microscope C) Darkfield microscope D) Fluorescence microscope E) Electron microscope

C

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.

C

A researcher is studying the number and arrangement of fimbriae covering the surface of a bacterial cell. Which type of microscopy would be most useful for this purpose? A.) Transmission electron microscopy B.) Scanning electron microscopy C.) Compound light microscopy D.) Darkfield microscopy

B

A student is observing an object that displays the internal detail on a virus at great magnification. Which type of microscope is used for this image? A.)Light microscope B.)Transmission electron microscope C.)Scanning acoustic microscope D.)Scanning electron microscope

B

Acid-fast staining is used to detect members of which bacterial genus? A.)Streptococcus B.)Mycobacterium C.)Clostridium D.)Staphylococcus

B

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

B

Most bacteria are in the __________ size range. A.) 1-10 nanometer B.)1-10 micrometer C.)0.5-1 centimeter D.)2-5 millimeter

B

Resolution is very good when using an electron microscope because the __________ of the electron beam is much shorter than that of visible light. A.) absorption B.)wavelength C.)penetration D.)reflection E.)frequency

B

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

B

The appearance of gram-negative bacteria after completing the Gram stain. A) Purple B) Red C) Colorless D) Brown E) None of the above

B

The greater resolution of the electron microscope compared to the compound microscope is due to the longer wavelengths of the electrons used to examine specimens. A.)True B.)False

B

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) None of the above.

B

The signal molecule produced in quorum sensing is A) Counterstain. B) Inducer. C) Light. D) Simple stain. E) None of the above

B

This 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

B

This microscope is used to see intracellular detail. A) Fluorescence microscope B) Phase-contrast microscope C) Darkfield microscope D) DIC microscope E) None of the above

B

This microscope takes advantage of differences in the refractive indexes of cell structures. A) Compound light microscope B) Phase-contrast microscope C) Darkfield microscope D) Fluorescence microscope E) Electron microscope

B

What is the role of lenses in microscopy? A.) Lenses are only used to magnify specimens that are smaller than whole red blood cells. B.) Lenses focus either light or electrons to create a magnified image of a specimen. C.)Lenses increase the contrast to determine structural differences in stained specimens

B

What structure does light pass through after leaving the condenser in a compound light microscope? A.)_illuminator B.)specimen C.)ocular lens D.)objective lens

B

Which of the following microscopes uses visible light? A) Confocal microscope B) DIC C) Fluorescence microscope D) Scanning acoustic microscope E) Scanning electron microscope

B

Which of the following types of microscopy is used to study the structure of the slimy accumulation of bacteria on an IV catheter tip? A.)Atomic force B.)Scanning acoustic C.)Confocal D.)Scanning electron E.)Phase-contrast

B

Which type of light microscopy is used to visualize stained specimens? A.)Phase-contrast B.)Brightfield C.)Compound D.)Darkfield E.)Binocular

B

__________ are too small to be seen with the light microscope without adding a mordant and carbolfuchsin. A.)Nuclei B.)Flagella C.)Mitochondria D.)Ribosomes

B

__________ is the quality of the microscope that allows one to distinguish between two points that are very close together A.) refractive index B.) resolution C.) magnification D.) oil immersion

B

of the following measurements is correctly matched with microorganisms of that size? A.)Viruses; 10 micrometers B.)Bacteria; 2 micrometers C.)Bacteria; 10 nanometers D.)Yeast; 1 centimeter

B

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

C

Van Leeuwenhoekʹs microscope was a(n) A) Electron microscope. B) Phase-contrast microscope. C) Simple microscope. D) Confocal microscope. E) None of the above.

C

What does resolution mean? A.) the total magnification of the visual image seen B.) the ability of a microscope to stay in focus when the objective lenses are moved from low power to high C.) the ability of a microscope to distinguish fine details and differentiate between two very close objects D.) a measure of the ability of a medium to bend light

C

What happens to the light rays when they hit the specimen? A.) They are absorbed by the stage. B.) They are focused into a small area towards the objective lens. C.)They are reflected, refracted, or absorbed by the specimen. D.) They are diverted to the ocular lens.

C

What is meant by light rays being divergent? A.) It is heading upwards B.)It is coming together to a focused beam C.)It is spreading out

C

What is the correct order for the Gram stain process? A.)malachite green → crystal violet → decolorizer → safranin B.)crystal violet → safranin → decolorizer → iodine C.)crystal violet → iodine → decolorizer → safranin D.)iodine → crystal violet → decolorizer → safranin

C

What is the fate of the electrons that interact with a specimen in an electron microscope? A.) They are refracted by the specimen. B.) They are reflected by the specimen. C.)They may be absorbed, reflected, or refracted by the specimen. D.) They are absorbed by the specimen.

C

What metric unit would be most appropriate for expressing the size of most viruses? A.)Millimeter B.)Centimeter C.)Nanometer D.)Micrometer

C

What structure does light pass through after leaving the condenser in a compound light microscope? A) Ocular lens B) Objective lens C) Specimen D) Illuminator

C

) 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

C

Image looks like a negative stain in this microscope: A) Fluorescence microscope B) Phase-contrast microscope C) Darkfield microscope D) DIC microscope E) None of the above

A

Nigrosin staining-not safranin staining-of Klebsiella pneumoniae will allow for the visualization of the cell shape and the determination of the presence of a capsule. A.)True B.)False

A

The appearance of gram-negative bacteria after addition of the mordant in the Gram stain. A) Purple B) Red C) Colorless D) Brown E) None of the above

A

The appearance of gram-positive bacteria after adding the counterstain in the Gram stain. A) Purple B) Red C) Colorless D) Brown E) None of the above

A

The appearance of gram-positive bacteria after addition of the first dye in the Gram stain. A) Purple B) Red C) Colorless D) Brown E) None of the above

A

The counterstain in the acid-fast stain is A) A basic dye. B) An acid dye. C) A negative stain. D) A mordant. E) Necessary to determine acid-fast cells.

A

The limit of resolution of the compound microscope illuminated with visible light is approximately 0.2 μm. A.)True B.)False

A

To obtain the measurement in nanometers, you have multiplied the measurement in micrometers by 1000. A.) true B.) false

A

What Gram reaction do you expect from acid-fast bacteria? A) Gram-positive B) Gram-negative C) Both gram-positive and gram-negative D) Canʹt tell

A

What does refraction mean? A.)A measure of the light-bending ability of a medium B.) The ability of a microscope to distinguish fine details and differentiate between two very close objects C.)The ability of a microscope to stay in focus when the objective lenses are moved from low to high magnification D.)The total magnification of the visual image seen

A

What is the role of the ocular lens? A.) To recreate the image in the viewer's eye B.) To focus the light to a high intensity in a small area C.)To do the bulk of the magnification D.)To adjust the wavelength of light

A

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

A

Why do electron microscopes have higher resolving power than light microscopes? A.)The fluorescent screen adds another magnification step. B.) They are capable of producing 3-dimensional images, which light microscopes cannot do. C.) The copper grid used in electron microscopy provides enhanced resolution. D.) Electrons have a smaller wavelength than visible light, leading to higher resolution.

D

Why is a specimen smaller than 200 nm not visible with a light microscope? A.) The lenses only go to 100 X magnification power. B.) Visible light is only good at wavelengths below 390 nm. C.) It is too easy to lose on the stage. D.) Anything smaller than 200 nm cannot interact with visible light.

D

is most useful for viewing the internal structures of unstained specimens. A.)Fluorescence B.)Brightfield C.)Electron D.)Phase-contrast E.)Confoca

D

microscopy, the specimen is illuminated by light passing through a ring-shaped diaphragm. Direct light rays travel a different path from light rays that are reflected or diffracted as they pass through the specimen. These two sets of rays are combined at the eye thus allowing this type of microscopy to show greater differentiation of internal structures of organisms. A.)Fluorescence B.)Brightfield C.)Electron D.)Phase-contrast E.)Confoca

D

) The best use of a negative stain is A) To determine cell size. B) To determine cell shape. C) To determine Gram reaction. D) To see endospores. E) A and B

E

An microscope uses a metal and diamond probe that is gently forced down along the surface of a specimen. As the probe moves along the surface of the specimen, its movements are recorded, and a three-dimensional image is produced A.)Scanning electron B.)Confocal C.)Scanning tunneling D.)Transmission electron E.)Atomic force

E

Immersion oil is necessary when using the 100x objective on a compound light microscope A.) otherwise too much light is lost to refraction. B.) to prevent the slide from scratching the lens. C.) to lubricate the objective. D.) otherwise the image will be fuzzy. E.) otherwise too much light is lost to refraction and the image will be fuzzy.

E

In a negative staining procedure, the bacterial cells would appear __________ when viewed under a microscope. A.)the same color as the background and thus not easily observed B.)stained in an unstained background C.)brightly colored in a contrasting background D.)attracted to the dye used in the staining procedure E.)unstained in a colored background

E

In this microscope, the observer does not look at an image through a lens. A) Compound light microscope B) Phase-contrast microscope C) Darkfield microscope D) Fluorescence microscope E) Electron microscope

E

Simple staining is often necessary to improve contrast in this microscope. A) Compound light microscope B) Phase-contrast microscope C) Darkfield microscope D) Fluorescence microscope E) Electron microscope

E

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.)make gram-negative cells visible. E.) prevent the crystal violet from leaving the cells

E

This 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

E

This microscope does not use a light. A) Compound light microscope B) Phase-contrast microscope C) Darkfield microscope D) Fluorescence microscope E) Electron microscope

E

This microscope is used to see detail of a 300 nm virus. A) Fluorescence microscope B) Phase-contrast microscope C) Darkfield microscope D) DIC microscope E) None of the above

E

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

E

When stained, bacteria in the genus Mycobacterium are __________. A.)Gram positive B.)All of the listed responses are correct. C.)Gram negative D.)None of the listed responses are correct. E.)acid fast

E

Which of the following is not correct? A) 1 μm = 10-6 m B) 1 nm = 10-9 m C) 1 μm = 103 nm D) 1 μm = 10-3 mm E) 1 nm = 10-6 μm

E

Which of the following statements is NOT true for both TEM and SEM? A.) Both can be used to view specimens smaller than 0.2 micrometers. B.)Black-and-white images are produced. C.)The illuminating source is an electron beam. D.)The microscope is focused using electromagnetic lenses. E.) The specimen must be sectioned before viewing.

E

You suspect a 100 nm structure is present in a cell. Which of the following provides the lowest magnification that 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

E

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

C

Which of the following is NOT a type of a compound microscope? A.)Fluorescence B.)Brightfield C.)Electron D.)Phase-contrast E.)Confoca

C

Which of the following is a characteristic shared by both electron and light microscopes? A.) They both utilize white light to magnify the specimen. B.) Both microscopes have a resolving power of 0.01 nm. C.) They both employ the use of objective lenses. D.) Both microscopes require an internal camera to visualize the specimen.

C

Which of the following is a lens found on electron microscopes but not on light microscopes? A.) Eyepiece lens B.) Objective lens C.) Projector lens D.) Condenser lens

C

Which of the following pairs is mismatched? A) Alcohol-acetone decolorizer B) Crystal violet basic dye C) Safranin acid dye D) Iodine mordant E) None of the above

C

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

C

) Bacterial smears are fixed before staining to A) Kill the bacteria. B) Affix the cells to the slide. C) Make their walls permeable. D) A and B. E) All of the above

D

) You find colorless areas in cells in a Gram-stained smear. What should you do next? A) An acid-fast stain B) A flagella stain C) A capsule stain D) An endospore stain E) A simple stain

D

1) Which of the following is not equal to 1 m? A) 106 μm B) 109 nm C) 10 dm D) 100 mm

D

Bacterial cells have an overall negative charge on their surface. If a bacterial smear is stained by a pink, acidic, water-soluble stain and then washed with water, which of the following describes the result that will be observed when viewing the stained slide under a microscope? A.)Unstained cells in a pink background B.)Purple cells C.)Pink cells in a pink background D.)Unstained cells with no background E.)Pink cells

D

If you use a compound light microscope, a 2-µm bacterial cell is best seen at which magnification? A.) 400X B.)100X C.)10X D.)1000X

D

In Figure 3.1 line B points to the microscopeʹs A) illuminator. B) condenser. C) ocular lens. D) objective lens

D

In the Gram stain, crystal violet is the __________. A.)decolorizing agent B.)counterstain C.)mordant D.)primary stain E.)fixative

D

In the Gram-stain procedure, a clear oval in the center of a cell could indicate __________. A.)lack of the central nucleoid B.)an unstained nucleus C.)the unstained bacterial chromosome D.)the presence of an endospore E.)a capsule

D

In the capsule stain using India ink, capsules are distinguished as __________ surrounding cells. A.)blue extensions B.)green shadows C.)pink circles D.)clear halos E.)purple rims

D

The purpose of a mordant in the Gram stain is A) To remove the simple stain. B) To make the bacterial cells larger. C) To make the flagella visible. D) To prevent the crystal violet from leaving the cells. E) None of the above.

D

This 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

D

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

D

This 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) None of the above

D

What is the total magnification of a chloroplast viewed with a 10 × ocular lens and a 45× objective lens? A) 10× B) 45× C) 100× D) 450× E) None of the above

D

When an object is viewed through a light microscope with oculars that magnify 20 20× and a high-power objective lens that magnifies 100 ×, what is the total magnification of the object? A.) 200× B.) 800 × C.) 1000× D.) 2000 ×

D

Which microscope is used to see detail of a 300-nm virus? A.) darkfield microscope B.) DIC microscope C.)fluorescence microscope D.) electron microscope E.) phase-contrast microscope

D

Which of the following pairs is mismatched? A.)carbolfuchsin - basic dye B.) crystal violet - basic dye C.) alcohol-acetone - decolorizer D.) safranin - acid dye E.)iodine - mordant

D

Which of the following types of microscopy is most useful for viewing the internal structures of unstained specimens? A.)Fluorescence B.)Brightfield C.)Electron D.)Phase-contrast E.)Confoca

D

Which type of microscope would allow the viewer to see ribosomes inside a cell? A.)A scanning electron microscope B.) A light microscope, transmission electron microscope, and scanning electron microscope can all view ribosomes inside a cell. C.)A light microscope D.) A transmission electron microscope

D

Which waxy molecule, found in the cell wall of acid-fast bacteria, prevents these cells from being Gram stained? A.)Carbolfuchsin B.)Methylene blue C.)Acid-alcohol D.)Mycolic acid

D

CONDENSER

microscope component that focuses light on objects under study

Which of the following describes the correct path of light in a compound light microscope, from the illumination source to the eye of the observer? A.) illuminator → condenser lenses → specimen → objective lenses → body tube → ocular lens → eye B.) Illuminator → ocular lens → body tube → condenser lenses → specimen → objective lenses → eye C.) objective lenses → specimen → illuminator → condenser lenses → body tube → ocular lens → eye D.) condenser lenses → illuminator → specimen → objective lenses → body tube → ocular lens → eye

A

Which of the following is NOT true regarding the acid-fast stain? A.) If cells are acid-fast, they are gram-negative. B.) It is used to identify members of the genus Mycobacterium. C.) Acid-fast cells retain the primary dye after treatment with acid-alcohol. 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.

A

Which of the following is the most convenient and appropriate unit for expressing the size of an average bacterial cell? A.)Micrometer B.)Centimeter C.)Millimeter D.)Nanometer

A

Which of the following pairs is mismatched? A) Gram-negative bacteria negative stain B) Iodine mordant C) Alcohol acetone-decolorizer D) Acid-alcohol decolorizer E) None of the above

A

Which of the following signs and symptoms is NOT associated with active pulmonary tuberculosis? A.) Weight gain B.) Fever C.) Chest pain D.) Cough with blood

A

Which of the following staining procedures is correctly matched with the principal use for that particular stain? A.)Endospore stain to distinguish dormant structures formed during adverse environmental conditions B.)Negative stain used to differentiate cell wall components C.)Flagella stain used to detect capsules D.)Acid-fast stain for microbes with capsules

A

Which of the following types of microscopy can be used to specifically identify pathogens (such as Mycobacterium tuberculosis or rabies virus) in specimens? A.)Fluorescence B.)Brightfield C.)Electron D.)Phase-contrast E.)Confoca

A

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

A

microscopy can be used to specifically identify pathogens. The diagnostic technique associated with this type of microscopy is called the fluorescent-antibody (FA) technique, or immunofluorescence. Fluorescent antibodies are added to a microscope slide containing an unknown bacterium. If the antigens are found on this unknown bacterium, the fluorescent antibodies bind to them, causing it to fluoresce. A.)Fluorescence B.)Brightfield C.)Electron D.)Phase-contrast E.)Confoca

A

• examining a clinical specimen, such as a sputum smear, for the presence of bacteria • examining a blood smear for the presence of malarial parasites A.) light microscope B.) scanning electron microscope C.)transmission electron microscope

A

Which of the following statements comparing electron microscopy and light microscopy is FALSE? A.) The electron microscope has greater resolution than the light microscope. B.) Electron microscopes can allow examination of viruses and internal cell structures, whereas light microscopes are limited to objects that are 0.5 micrometers and larger. C.) Both the electron microscope and the light microscope use the same wavelengths for illumination. D.) Images produced by light microscopes can be in color, whereas electron microscope images are black and white unless they are artificially colored.

C

Which of the following types of microscopy provides advantages for viewing live images? A.) scanning electron microscopy B.) transmission electron microscopy C.) darkfield microscopy D.) fluorescent microscopy

C

Which type of light microscopy is used to visualize stained specimens? A.)Darkfield B.)Phase-contrast C.)Brightfield D.)Binocular E.)Compound

C

__________ is an example of an acidic dye; __________ is an example of a basic dye. A.)safranin; methylene blue B.)malachite green; eosin C.)nigrosin; crystal violet D.)acid fuchsin; ink

C

__________ is important in medical microbiology because the results help physicians select appropriate antibiotics for treatment. A.)Simple staining B.)The observation of the size of bacteria C.)Gram staining D.)The observation of morphology of bacteria

C

• viewing ribosomes (20 nm) within a bacterial cell • confirming the 9 + 2 microtubule arrangement in a eukaryotic flagellum • viewing a cross section of poliovirus (30 nm) • viewing the layers of the gram-negative cell wall in cross section A.) light microscope B.) scanning electron microscope C.)transmission electron microscope

C

phase contrast light microscopy

Microscope amplifies differences in phase of light transmitted or reflected by sample; Improved contrast of denser structures; Can be used to view living UNSTAINED cells