Question 1

Explain phase-contrast microscopy and give one advantage and one disadvantage of phase-contrast microscopy.

Accepted Answer

Phase-contrast microscopy exploits diffe

Question 2

What is the key property that enables a lens to magnify an image?

Accepted Answer

A)  reflection 
B)  resolution 
C)  frequency 
D)  refraction 
E)  wavelength 
A)  reflection 
B)  resolution 
C)  frequency 
D)  refraction 
E)  wavelength

Question 3

X-ray diffraction and phase contrast microscopy both involve:

Accepted Answer

A)  wave interference 
B)  observation of living specimens 
C)  differential stains 
D)  simple stains 
E)  shadowing. 
A)  wave interference 
B)  observation of living specimens 
C)  differential stains 
D)  simple stains 
E)  shadowing.

Question 4

An image is magnified when light passes through a refractive material shaped so as to __________ its rays.

Accepted Answer

A)  absorb 
B)  block 
C)  concentrate 
D)  condense 
E)  spread 
A)  absorb 
B)  block 
C)  concentrate 
D)  condense 
E)  spread

Question 5

Compare and contrast the radiation source, the lenses, and the image-capturing device in light and TEM.

Accepted Answer

The radiation source for light microscop

Question 6

The knife used to cut embedded specimens for observation by TEM is called a:

Accepted Answer

A)  crystallographer 
B)  microtome 
C)  grid 
D)  polymer 
E)  scalpel 
A)  crystallographer 
B)  microtome 
C)  grid 
D)  polymer 
E)  scalpel

Question 7

Which type of microscopy is particularly useful to study the surfaces of live bacteria?

Accepted Answer

A)  atomic force 
B)  SEM 
C)  TEM 
D)  dark-field 
E)  bright-field 
A)  atomic force 
B)  SEM 
C)  TEM 
D)  dark-field 
E)  bright-field

Question 8

Why are stains used in microscopy? Compare and contrast the stains used in light versus electron microscopy.

Accepted Answer

Stains are used to increase the contrast

Question 9

In which one of the following types of microscopy is the specimen shadowed with heavy metal?

Accepted Answer

A)  atomic force microscopy 
B)  SEM 
C)  TEM 
D)  X-ray diffraction 
E)  dark-field 
A)  atomic force microscopy 
B)  SEM 
C)  TEM 
D)  X-ray diffraction 
E)  dark-field

Question 10

A/An __________ acts to vary the diameter of the light column in a light microscope.

Accepted Answer

A)  condenser 
B)  objective 
C)  ocular 
D)  diaphragm 
E)  lens 
A)  condenser 
B)  objective 
C)  ocular 
D)  diaphragm 
E)  lens

Question 11

Give a few reasons why living organisms may NOT be observed by TEM or SEM.

Accepted Answer

In TEM, the specimens are fixed and embe

Question 12

The fluorophore acridine orange specifically binds:

Accepted Answer

A)  cytoplasm 
B)  cell wall 
C)  protein 
D)  RNA 
E)  DNA 
A)  cytoplasm 
B)  cell wall 
C)  protein 
D)  RNA 
E)  DNA

Question 13

When two waves are out of phase by __________ wavelength, they produce destructive interference, canceling each other's amplitude and resulting in contrast in the image.

Accepted Answer

A)  one-tenth 
B)  one-eighth 
C)  one-quarter 
D)  one-half 
E)  one 
A)  one-tenth 
B)  one-eighth 
C)  one-quarter 
D)  one-half 
E)  one

Question 14

Eukaryotes stain:

Accepted Answer

A)  Gram-neutral 
B)  Gram-positive 
C)  Gram-negative 
D)  blue 
E)  no color 
A)  Gram-neutral 
B)  Gram-positive 
C)  Gram-negative 
D)  blue 
E)  no color

Question 15

A rod-shaped microbe is referred to as a:

Accepted Answer

A)  bacillus 
B)  coccus 
C)  vibrio 
D)  strepto 
E)  spirochete 
A)  bacillus 
B)  coccus 
C)  vibrio 
D)  strepto 
E)  spirochete

Question 16

Fixatives and heavy atom stains used in EM can introduce __________ into an image.

Accepted Answer

A)  colors 
B)  resolution 
C)  refraction 
D)  artifacts 
E)  fluorescence 
A)  colors 
B)  resolution 
C)  refraction 
D)  artifacts 
E)  fluorescence

Question 17

Explain when you would use Bacillus versus bacillus.

Accepted Answer

Bacillus refers to a genus of organisms.

Question 18

Which form of microscopy is based on the difference in refractive index between cell components and the surrounding medium?

Accepted Answer

A)  bright-field 
B)  dark-field 
C)  phase contrast 
D)  confocal 
E)  fluorescence 
A)  bright-field 
B)  dark-field 
C)  phase contrast 
D)  confocal 
E)  fluorescence

Question 19

All electromagnetic radiation travels through a vacuum at what speed?

Accepted Answer

A)  3 × 108 mm/sec 
B)  3 × 108 cm/sec 
C)  3 × 108 m/sec 
D)  3 × 108 ft/sec 
E)  3 × 108 mph 
A)  3 × 108 mm/sec 
B)  3 × 108 cm/sec 
C)  3 × 108 m/sec 
D)  3 × 108 ft/sec 
E)  3 × 108 mph

Question 20

Why do some bacteria appear purple after being Gram stained and other appear red?

Accepted Answer

Gram-negative cells have a few layers of

Exam 2: Observing the Microbial Cell

Explain phase-contrast microscopy and give one advantage and one disadvantage of phase-contrast microscopy.

What is the key property that enables a lens to magnify an image?

X-ray diffraction and phase contrast microscopy both involve:

An image is magnified when light passes through a refractive material shaped so as to __________ its rays.

Compare and contrast the radiation source, the lenses, and the image-capturing device in light and TEM.

The knife used to cut embedded specimens for observation by TEM is called a:

Which type of microscopy is particularly useful to study the surfaces of live bacteria?

Why are stains used in microscopy? Compare and contrast the stains used in light versus electron microscopy.

In which one of the following types of microscopy is the specimen shadowed with heavy metal?

A/An __________ acts to vary the diameter of the light column in a light microscope.

Give a few reasons why living organisms may NOT be observed by TEM or SEM.

The fluorophore acridine orange specifically binds:

When two waves are out of phase by __________ wavelength, they produce destructive interference, canceling each other's amplitude and resulting in contrast in the image.

Eukaryotes stain:

A rod-shaped microbe is referred to as a:

Fixatives and heavy atom stains used in EM can introduce __________ into an image.

Explain when you would use Bacillus versus bacillus.

Which form of microscopy is based on the difference in refractive index between cell components and the surrounding medium?

All electromagnetic radiation travels through a vacuum at what speed?

Why do some bacteria appear purple after being Gram stained and other appear red?

Microbial Life: Origin and Discovery

Cell Structure and Function

Bacterial Culture, Growth, and Development

Environmental Influences and Control of Microbial Growth

Virus Structure and Function

Genomes and Chromosomes

Transcription, Translation, and Bioinformatics

Gene Transfer, Mutations, and Genome Evolution

Molecular Regulation

Viral Molecular Biology

Molecular Techniques and Biotechnology

Energetics and Catabolism

Respiration, Lithotrophy, and Photolysis

Biosynthesis

Food and Industrial Microbiology

Origins and Evolution

Bacterial Diversity

Archaeal Diversity

Eukaryotic Diversity

Microbial Ecology

Microbes and the Global Environment

Human Microbiota and Nonspecific Host Defenses

The Adaptive Immune Response

Microbial Pathogenesis

Microbial Diseases

Antimicrobial Chemotherapy

Clinical Microbiology and Epidemiology

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