Deck 4: Microscopy, Staining, and Classification

Question 1

The kingdoms included in the Linnaeus system are

A) Animalia and Prokaryotae.
B) Protista and Plantae.
C) Fungi and Protista.
D) Animalia and Plantae.
E) Prokaryotae and Protista.

Answer 1

D

Question 2

The microscope preferred for viewing living specimens is the __________ microscope.

A) bright-field
B) phase-contrast
C) scanning electron
D) scanning tunneling
E) transmission electron

Answer 2

B

Question 3

Carbolfuchsin is the __________ in the acid-fast stain.

A) primary stain
B) mordant
C) decolorizer
D) counterstain
E) fixing reagent

Answer 3

A

Question 4

Which of the following microscopes produces the highest resolution images?

A) dark-field
B) differential interference
C) scanning electron
D) fluorescent
E) atomic force

Question 5

Which of the following staining procedures use(s) heat to drive the stain in?

A) endospore stain
B) acid-fast stain
C) capsule stain
D) Gram stain
E) both acid-fast and endospore stains

Question 6

All of the following are components of electron microscopy stains EXCEPT

A) eosin.
B) tungsten.
C) lead.
D) uranium.
E) osmium.

Question 7

Which of the following is an incorrect pairing?

A) magnification: refraction of radiation
B) contrast: staining techniques
C) numerical aperture: curved glass
D) simple microscope: Leeuwenhoek
E) electron beams: shorter wavelength

Question 8

A patient suffering from tuberculosis could be diagnosed by use of the __________ stain.

A) Gram
B) endospore
C) acid-fast
D) flagellar
E) capsule

Question 9

The ability of a lens to gather light is referred to as its

A) resolution.
B) numerical aperture.
C) refraction.
D) contrast.
E) magnification.

Question 10

All of the following are associated with different types of phase microscopes EXCEPT

A) a dark-field stop.
B) a phase plate.
C) Nomarski microscopes.
D) unstained specimens.
E) prisms.

Question 11

Which of the following is(are) (a) magnifying lens(es)?

A) objective
B) ocular
C) condenser
D) dark-field stop
E) both the objective and the ocular

Question 12

Which of the following is NOT associated with an electron microscope?

A) an electron beam
B) magnetic fields
C) a prism
D) a fluorescent screen
E) a vacuum

Question 13

If you were trying to visualize flagella without staining, which microscope would you use?

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

Question 14

Cellular organelles and viruses are generally measured in

A) nanometers.
B) millimeters.
C) micrometers.
D) centimeters.
E) decimeters.

Question 15

Why does immersion oil improve resolution?

A) It allows light to travel at a uniform speed on its way to the lens.
B) It decreases the working distance.
C) It increases the numerical aperture.
D) It increases numerical aperture and maintains a uniform light speed.
E) It increases the angle of refraction of the light.

Question 16

A staining procedure used to detect fungi in tissue samples is the __________ stain.

A) acid- fast
B) endospores
C) Gram
D) Gomori methenamine silver (GMS)
E) hematoxylin and eosin (HE)

Question 17

All of the following are types of light microscopes EXCEPT

A) fluorescent.
B) confocal.
C) phase-contrast.
D) scanning tunneling.
E) bright-field.

Question 18

All of the following are common to both the Gram stain and the acid-fast stain EXCEPT

A) primary stain.
B) counterstain.
C) a decolorizing agent.
D) a mordant.
E) a decolorizing agent and a counterstain.

Question 19

The rules of naming organisms are called

A) taxonomy.
B) nomenclature.
C) classification.
D) binomials.
E) identification.

Question 20

If a microbiology lab technician left the safranin out of the Gram stain procedure, what would be the result?

A) All cells would be purple.
B) Gram-positive cells would be purple, and Gram-negative cells would be colorless.
C) All cells would be pink.
D) Gram-positive cells would be pink, and Gram-negative cells would be purple.
E) Gram-positive cells would be colorless, and Gram-negative cells would be pink.

Question 21

Why have some microbiologists proposed using ribosomal RNA as the basis for defining bacterial species?

A) Ribosomal RNAs are highly conserved genetic sequences present in all prokaryotes.
B) the "interbreeding population" criterion does not apply to bacteria.
C) ribosomal RNA is the basis for domain assignment.
D) bacteria vary too little in their physical and biochemical traits.
E) bacteria are not interbreeding populations, and ribosomal RNAs are highly conserved genes present in all prokaryotes.

Question 22

Which of the following is NOT a characteristic of a genus name?

A) it is usually an adjective.
B) it is written before the specific epithet.
C) it is always capitalized.
D) it is either underlined or in italics.
E) it is one of two names used to identify an organism.

Question 23

Which category of microbe is NOT included in Woese' taxonomic scheme?

A) animals
B) bacteria
C) fungi
D) protista
E) viruses

Question 24

Why are modern light microscopes better than the ones Leeuwenhoek used?

A) Modern microscopes have a fivefold better resolution.
B) Modern microscopes are compound instead of simple.
C) Modern microscopes have lenses with smaller numerical apertures.
D) Modern lenses are made of prisms.
E) Modern microscopes are compound and have fivefold better resolution.

Question 25

Acidic dyes

A) work best in low pH environments.
B) are negatively charged.
C) are used for staining negatively charged molecular structures.
D) are lipid soluble.
E) are negatively charged and work best at low pH.

Question 26

What role does safranin play in the Gram stain procedure?

A) primary stain
B) mordant
C) decolorizing agent
D) counterstain
E) negative stain

Question 27

In Gram staining, ethanol-acetone is used as a

A) decolorizing agent.
B) counterstain.
C) mordant.
D) drying agent.
E) primary stain.

Question 28

Which of the following statements about transmission electron microscopy is FALSE?

A) Thin segments must be used.
B) Electrons are the source of illumination.
C) Glass lenses are used.
D) The sample is placed in a vacuum.
E) Stains can be applied to improve contrast.

Question 29

The Gram stain works because of differences in the __________ of bacteria.

A) genetic characteristics
B) cell walls
C) cell membranes
D) antigens
E) capsules

Question 30

Which of the following classification methods relies on the morphology of organisms?

A) phage typing
B) physical characteristics
C) biochemical tests
D) analysis of nucleic acids
E) serological tests

Question 31

Osmium tetraoxide is a reagent used in the

A) acid-fast stain.
B) electron microscopy stain.
C) endospore stain.
D) flagellar stain.
E) negative stain.

Question 32

All of the following are associated with smear preparation EXCEPT

A) agglutination of the specimen.
B) spreading the specimen onto a slide.
C) fixation using heat.
D) killing the microbes in the specimen.
E) fixation using methanol or formalin.

Question 33

Which of the following phenomena produces magnification?

A) the wavelength of a radiation source
B) the refraction of radiation as it passes through a lens
C) the thickness of a microscopic specimen
D) the numerical aperture of a lens
E) the length of an objective lens

Question 34

The primary goal of modern taxonomists is to

A) have a complete inventory of all living things.
B) establish unique identifiers for each species.
C) determine what defines a species.
D) understand the phylogenetic relationships between organisms.
E) There is no consensus among modern taxonomists regarding their primary goal.

Question 35

A virologist wants to observe the surface features of virus particles she is studying. Which of the following microscopes would NOT be useful for her observations?

A) differential interference contrast
B) scanning tunneling
C) scanning electron
D) transmission electron
E) atomic force

Question 36

Crystal violet is the __________ in the Gram stain.

A) counterstain
B) decolorizing agent
C) mordant
D) neutralizing agent
E) primary stain

Question 37

A structure that appears in a transmission electron micrograph but is not actually present in the specimen is known as a(n)

A) antigen.
B) biofilm.
C) artifact.
D) refraction.
E) mordant.

Question 38

Carl Woese proposed the concept of the domain based on differences of which of the following cellular molecules?

A) transfer RNA
B) membrane lipids
C) ribosomal RNA
D) DNA
E) proteins

Question 39

A cell's G + C ratio is associated with which of the following classification methods?

A) phage typing
B) biochemical tests
C) physical characteristics
D) analysis of nucleic acids
E) serological tests

Question 40

In the Gram stain procedure, iodine serves as a

A) counterstain.
B) decolorizing agent.
C) mordant.
D) primary stain.
E) fixative.

Question 41

A resolution of 1 μm would be better than a resolution of 0.5 μm.

Question 42

Which staining procedure makes use of pararosanaline?

A) negative stain
B) flagellar stain
C) endospore stain
D) electron microscopy stain
E) acid-fast stain

Question 43

Members of the genera Bacillus and Clostridium can be identified using the endospore stain.

Question 44

Bacterial cells are so similar to each other that physical characteristics cannot be used in identifying organisms.

Question 45

Gram staining of bacteria provides all the physical characterization necessary to identify bacterial species.

Question 46

The three domains proposed by Carl Woese are the Archaea, the Eukarya, and the Protista.

Question 47

The size of a pork tapeworm is generally described in terms of

A) meters (m).
B) millimeters (mm.)
C) micrometers (µm).
D) nanometers (nm).
E) decimeters (dc).

Question 48

The most appropriate unit of measurement for intact archaea is the

A) meter (m).
B) millimeter (mm).
C) micrometer (µm).
D) nanometer (nm).
E) centimeter (cm).

Question 49

Methylene blue is a reagent in the

A) acid-fast stain.
B) negative stain.
C) flagellar stain.
D) endospore stain.
E) electron microscopy stain.

Question 50

Three-dimensional images of specimens can be obtained using scanning electron microscopes.

Question 51

Light rays that pass through the edge of a curved lens will be refracted more than those that pass through the center.

Question 52

Acid-fast cells such as Mycobacterium lose the color of the primary stain in the presence of hydrochloric acid.

Question 53

The __________ is one in which eosin is used.

A) acid-fast stain
B) negative stain
C) flagellar stain
D) endospore stain
E) electron microscopy stain

Question 54

The Gram stain can be used to distinguish bacteria based on the structure of their cell walls.

Question 55

The __________ makes use of malachite green.

A) negative stain
B) flagellar stain
C) endospore stain
D) electron microscopy stain
E) acid-fast stain

Question 56

A tick is usually measured in terms of

A) meters (m).
B) millimeters (mm).
C) micrometers (µm).
D) nanometers (nm).
E) yards.

Question 57

Light rays that are in phase reinforce each other and produce a brighter image.

Question 58

Bacterial cells are usually a few __________ in size.

A) centimeters (cm)
B) millimeters (mm)
C) micrometers (µm)
D) nanometers (nm)
E) meters (m)

Question 59

A(n) __________ microscope has a single ocular lens.

Question 60

The dimensions of a virus are usually described in

A) meters (m).
B) millimeters (mm).
C) micrometers (µm).
D) nanometers (nm).
E) centimeters.

Question 61

A(n) __________ molecule is one that absorbs invisible radiation and emits visible light.

Question 62

Compare and contrast the three domains identified by Woese: Eukarya, Bacteria, and Archaea.

Question 63

An integral part of serological testing is the use of a solution called __________ that contains antibodies.

Question 64

A staining procedure that uses a single basic dye is called a(n) __________ stain.

Question 65

Carl Woese and his colleagues proposed the __________, a taxon that contains multiple kingdoms.

Question 66

Coating a specimen with a heavy metal is a step in preparing it for __________ microscopy.

Question 67

Compare and contrast the light microscope with the electron microscope.

Question 68

The limit of resolution of the unaided human eye is about __________ μm. (Be sure your answer is a numeral.)

Question 69

In a compound microscope, the lens that directs light through the specimen is the __________ lens.

Question 70

The system of taxonomy used today was originated by __________. (Be sure to capitalize your answer.)

Question 71

Discuss the ways in which light rays can be manipulated to increase resolution and/or contrast.

Question 72

The process of immobilizing organisms on a glass slide through the application of either heat or chemicals is __________.

Question 73

List and explain five types of techniques that can be used to identify unknown microorganisms.

Question 74

Bacterial viruses, called __________, can be used to help classify different groups of bacteria.

Question 75

A(n) __________ key is a guide that directs the user through a step-by-step process to identify a microbe.

Question 76

The total magnification using a 10 ocular and a 100 objective would be __________ X. (Be sure your answer is a numeral.)

Question 77

A serological test that involves the clumping of antigen and antibody is the __________ test.

Question 78

A(n) __________ is a substance that binds to a dye and makes it less soluble.

Question 79

You are a scientist studying the highly specific interactions of bacteriophages with their host cells when they first encounter the cell. Discuss what microscope(s) and preparation procedures you might use for this study.