Chapter Quizzes: 3.2, 4, 6
The majority of human viral infections are fatal. True or False
False(Most viral infections do not result in death, although there are some viruses (Ebola, rabies) which have a very high mortality. )
Which species cultured on this plate possesses the largest capsule? Multiple Choice Proteus Klebsiella S. aureus
Klebsiella
Select all of the terms that can be accurately used to describe a virus. Check All That Apply Obligate intracellular parasite Infectious particle Live organism Live organism Dead particle Dead particle
Obligate intracellular parasite Infectious particle
Select all of the structures that are found in a gram-negative cell envelope. Check All That Apply Thick layer of peptidoglycan Outer membrane Periplasmic space Cell membrane Teichoic acids Lipopolysaccharide Lipoteichoic acids Thin layer of peptidoglycan
Outer membrane Periplasmic space Cell membrane Lipopolysaccharide Thin layer of peptidoglycan
Which term refers to the arrangement of bacilli in side-by-side rows? Multiple Choice Vibrio Palisade Spirochete Sarcina
Palisade
Which type of microscopy transforms the subtle variations in cell density into differences in light intensity, allowing for increased internal detail without staining? Multiple Choice Phase-contrast Electron Fluorescence Confocal Bright-field
Phase-contrast
What component provides for a stronger cell wall structure in gram-positive cells in comparison to gram-negative cells? Multiple Choice Thick peptidoglycan layer Teichoic acids Lipopolysaccharide Phospholipids Outer membrane
Thick peptidoglycan layer
The bacterial flagellum has three components. In order from the cytoplasm to the external environment, they are ______. Multiple Choice hook, basal body, and filament filament, basal body, and hook filament, hook, and basal body basal body, filament, and hook basal body, hook, and filament
basal body, hook, and filament
A differential interference contrast microscope uses dyes to give colored, three-dimensional images. True or False
false
Following a properly-performed Gram stain, gram-positive bacteria will appear as pink or red cells. True or False
false
Gram-positive bacteria have flagella with four basal body rings, while those of gram-negative bacteria have only two. True or False
false
The _____ of the microscope holds and allows selection of the objective lenses. Multiple Choice condenser nosepiece stage ocular
nosepiece
Variations in the size and shape of cells within a single species of bacteria is known as ______. Multiple Choice hermaphrodism pleotropism pleomorphism plasticity
pleomorphism
Mad cow disease is caused by a noncellular infectious agent called a _____. Multiple Choice prion scrapie viroid satellite virus
prion
The type of microscopy in which you would observe brightly illuminated specimens against a black background is ______. Multiple Choice fluorescence phase-contrast confocal electron dark-field
dark-field
Staphylococcus
Grape-like (irregular) cluster of spheres
All of the following are diameters of cells that would be resolved in a microscope with a limit of resolution of 0.2 µm except ______. Multiple Choice 0.2 mm 2.0 µm 0.1 µm 0.2 µm
0.1 µm
Order the following steps to reflect the order in which they occur in the life cycle of an animal virus. Ranking Assembly of viral particle Synthesis of viral nucleic acid and proteins Adsorption (attachment) to host cell surface Penetration and uncoating Release from host cell
1. Adsorption (attachment) to host cell surface 2. Penetration and uncoating 3. Synthesis of viral nucleic acid and proteins 4. Assembly of viral particle 5. Release from host cell
Order the following choices to reflect the correct steps in the process of sporogenesis. -Vegetative cell becomes a sporangium. -Endospore formation is initiated in response to environmental signals. -The mature spore is released and can remain dormant for thousands of years. -A forespore forms, and calcium and dipicolinic acid are deposited. -Protein spore coats are added.
1. Endospore formation is initiated in response to environmental signals. 2. Vegetative cell becomes a sporangium. 3. A forespore forms, and calcium and dipicolinic acid are deposited. 4. Protein spore coats are added. 5. The mature spore is released and can remain dormant for thousands of years.
Order the following choices in terms of size, from smallest to largest. Ranking Bacteria Yeast Helminths Viruses
1. virus 2. bacteria 3. yeast 4. helminths
Cells of Staphylococcus aureus are cocci measuring about 1 μm in diameter. In a textbook image of S. aureus, each cell measures about 1 cm. The magnification of the image on the page is ______. Multiple Choice 10,000X 1,000X 100X 0.01X 0.001X 0.0001X This is impossible to calculate without more information.
10,000X
If a microbiologist is studying a specimen at a total magnification of 950X, what is the magnifying power of the objective lens if the ocular lens is 10X? Multiple Choice 950X 9500X 95X 940X
95X
Which type of microscope shows cells against a white background? Multiple Choice Fluorescence Electron Bright-field Phase-contrast Confocal
Bright-field
Streptobacillus
Chain of rods
Choose the statement that best describes how bacteria respond to chemical attractants. Multiple Choice Chemical attractants cause bacterial cells to grow additional flagella. Chemical attractants inhibit tumbles, enabling bacteria to make faster progress toward the stimulus. Chemical attractants cause flagella to rotate clockwise. Chemical attractants speed up the rotation rate of flagella.
Chemical attractants inhibit tumbles, enabling bacteria to make faster progress toward the stimulus.
Select characteristics exhibited by all bacteria. Check All That Apply Chromosome Fimbriae Capsule Ribosomes Cell Wall Flagella Endospores Cell membrane
Chromosome cell membrane Ribosomes
Sarcina
Cubical packet of 8, 16, or more spherical cells
Bacillus
Cylindrical or rod-shaped cell
Which of the following cell arrangements is/are described correctly? Multiple Choice a. Staphylococcus - Chains of spherical cells b. Streptococcus - Grape-like clusters of spherical cells c. Diplococcus - Pairs of spherical cells d. Staphylococcus - Chains of spherical cells and Streptococcus - Grape-like clusters of spherical cells e. Staphylococcus - Chains of spherical cells, Streptococcus - Grape-like clusters of spherical cells and Diplococcus - Pairs of spherical cells
Diplococcus - Pairs of spherical cells
Which type of microscope achieves the greatest resolution and highest magnification? Multiple Choice Bright-field Phase-contrast Electron Fluorescence Dark-field
Electron
Which type of microscope does not use light in forming the specimen image? Multiple Choice Fluorescence Bright-field Dark-field Phase-contrast Electron
Electron
Chemical analysis of a bacterial cell detects dipicolinic acid. What is the identity of this structure? Multiple Choice Endospore Capsule Cell wall Nucleoid Biofilm
Endospore
Viruses are inactive macromolecules inside of a host cell. True or False
False (Viruses are merely inactive macromolecules outside of a host cell. Inside of a host cell, they can take over the cellular machinery for replication.)
Select the bacterial appendage that enables bacteria to stick to one another, to inanimate surfaces, and to host cells. Multiple Choice Cell wall Pili Axial filaments Flagella Fimbriae
Fimbriae
Select the structures that enable bacteria to be motile. Check All That Apply Pili Flagella Axial filaments Fimbriae Glycocalyx Pseudopods
Flagella Axial filaments
Select the structures that are possessed by some, but not all, bacteria. Check All That Apply Flagella Cell membrane Endospores Ribosomes Pili Fimbriae Glycocalyx
Flagella Endospores Pili Fimbriae Glycocalyx
In which situation would a bacterium most likely have cytoplasmic inclusions? Multiple Choice When the cell is synthesizing flagella In a habitat abundant in nutrients When the cell is starved for nutrients When producing an endospore
In a habitat abundant in nutrients
Who invented the first crude microscope by grinding glass? Multiple Choice Pasteur Lister Leeuwenhoek Schultz and Schwann Redi
Leeuwenhoek
Choose the term that describes a bacteriophage infection in which the host bacteria are lysed and killed by the infection. Multiple Choice Transforming Hemorrhagic Lysogenic Lytic Oncogenic
Lytic(A lytic infection occurs when a bacteriophage infects bacteria, and the bacteria are ruptured or lysed as a result of the infection.)
The simple microscopes used by the earliest practitioners of microscopy contained which of the following? Multiple Choice Condenser Oil-immersion lens Ocular Magnifying lens
Magnifying lens
A bacterial genus that has waxy mycolic acid in the cell walls is ______. Multiple Choice Mycobacterium Streptococcus Bacillus Mycoplasma Corynebacterium.
Mycobacterium
What condition triggers sporogenesis among endospore-forming bacteria? Multiple Choice Nutrient depletion Excess heat Ultraviolet light exposure Lack of water Presence of toxic chemicals
Nutrient depletion (particularly the depletion of carbon or nitrogen. )
Which of the following parts of a microscope magnifies the specimen to produce a real image of the specimen? Multiple Choice Objective lens Nosepiece Condenser Ocular lens Body
Objective lens
Which of the following parts of the microscope magnifies the specimen to produce the virtual image of the specimen? Multiple Choice Objective lens Body Ocular lens Condenser
Ocular lens
A microbiology student with a visual disability is viewing a sample of Bacillus endospores in a phase contrast microscope that is linked to an iPad. By "stretching" the image on the iPad screen, the student can increase the apparent size of the endospores. How does this manipulation affect resolution and contrast? (No software is being used to alter the image!) Multiple Choice Resolution and magnification will decrease because the screen is not as good as the human eye. Both magnification and resolution increase; contrast is unchanged. Only the magnification can be increased; resolution and contrast are unchanged. Contrast will improve because the microscope is phase-contrast.
Only the magnification can be increased; resolution and contrast are unchanged.
During bacterial conjugation, DNA can be transferred from the donor cell to the recipient cell through which structure? Multiple Choice Pilus Axial filament Fimbria Flagellum
Pilus
Humans can see objects as small as 0.1 mm. Leeuwenhoek's best microscope could magnify objects to 300X. Which of the following would be invisible using Leeuwenhoek's microscope? Pandora virus, 0.5 mm X 1 mm Escherichia coli, 1 μm X 4 μm Poliovirus, 30 nm Correct Red blood cell, 8 μm
Poliovirus, 30 nm
Select the infectious agents that are noncellular. Check All That Apply Bacteria Prions Satellite viruses Protozoa Viroids
Prions Satellite viruses Viroids
Choose the phrase that best describes the role of viral surface proteins or spikes. Multiple Choice Inject viral nucleic acid into host cell Allow viruses to bind to each other Provide means of attachment to host cell surface Provide means for viruses to exchange nucleic acid Enable replication of the viral nucleic acid
Provide means of attachment to host cell surface
Which term refers to the microscope's ability to show two separate objects as discrete and distinct? Multiple Choice Refraction Resolution Magnification Contrast
Resolution
Which type of microscope bombards a whole, metal-coated specimen with electrons moving back and forth over it? Multiple Choice Fluorescence Differential interference contrast Phase-contrast Scanning electron Transmission electron
Scanning electron
Select the terms that describe the possible configurations of viral nucleic acids. Check all that apply. Check All That Apply Single-stranded DNA Double-stranded DNA - linear Double-stranded DNA-RNA hybrid Double-stranded DNA - circular Single-stranded RNA, positive-sense Single-stranded RNA, negative-sense Double-stranded RNA
Single-stranded DNA Double-stranded DNA - linear Double-stranded DNA - circular Single-stranded RNA, positive-sense Single-stranded RNA, negative-sense Double-stranded RNA
Which of the following is involved in gliding motility in bacteria? Multiple Choice Specialized cell-surface proteins Slimy polysaccharides Flagella Specialized cell-surface proteins and slimy polysaccharides Specialized cell-surface proteins, slimy polysaccharides and flagella
Specialized cell-surface proteins and slimy polysaccharides
Tetrad
Spheres in a group of four
Coccus
Spherical cell
Spirillum Spirochete
Spiral or helical-shaped cell
Which of the following statements about flagellar structure is TRUE? Multiple Choice The hook anchors the flagellum in the cell membrane. The basal body is a short curved segment. The filament extends out of the cell. The hook anchors the flagellum in the cell membrane and the basal body is a short curved segment. The hook anchors the flagellum in the cell membrane, the basal body is a short curved segment and the filament extends out of the cell.
The filament extends out of the cell.
What do the Gram stain, the acid-fast stain, and the endospore stain have in common? Multiple Choice The staining outcome varies with the charge of the cell wall. They use a negative stain technique. They are used on a wet mount of the specimen. They are differential stains. They use heat to force the dye into cell structures.
They are differential stains.
select all of the structures that are found in a gram-positive cell envelope. Check All That Apply Outer membrane Cell membrane Teichoic acids Lipopolysaccharide Lipoteichoic acids Thin layer of peptidoglycan
Thick layer of peptidoglycan Cell membrane Teichoic acids Lipoteichoic acids
Comparing transmission electron microscopy with scanning electron microscopy, the following statement is true. Multiple Choice Transmission EM is used for internal detail of cells and subcellular structures. Transmission EM can provide good images of bacteria but not viruses. Transmission EM gives detail of the external architecture of cells. Transmission EM requires dyes.
Transmission EM is used for internal detail of cells and subcellular structures.
Select the three methods that are used to cultivate viruses. Check All That Apply Use of cell culture techniques Use of enriched agar media Use of animal inoculation Inoculation of eggs that contain embryos Use of enriched broth media
Use of cell culture techniques Use of animal inoculation Inoculation of eggs that contain embryos
Choose the statement that correctly explains why viruses are referred to as "filterable." Multiple Choice Viruses are able to pass through a filter because of their high density. Viruses are able to pass through a filter because of their small size. Viruses are able to pass through a filter because of the negative charge on their surface. Viruses are able to pass through a filter because they lack peptidoglycan in their envelope. Viruses are not able to pass through filters.
Viruses are able to pass through a filter because of their small size.(iruses are described as "filterable agents." This discovery was made in the late nineteenth century, when researchers found that filters that would normally retain bacteria would not retain viruses. Viruses would pass through. This is because of the extremely small size of the viruses. They are smaller than the pore size of the filter.)
Select all of the facts that support the concept that viruses are nonliving agents. Check All That Apply Viruses can direct life processes within a cell. Viruses are not able to reproduce outside of a host cell. Viruses have DNA or RNA, but not both. Viruses are unable carry out metabolic processes to generate ATP. Viruses have genetic material that determines their traits. Viruses can reproduce provided they have a host cell. Viruses can evolve. Viruses do not have a cellular structure.
Viruses are not able to reproduce outside of a host cell. Viruses have DNA or RNA, but not both. Viruses are unable carry out metabolic processes to generate ATP. Viruses do not have a cellular structure.
Select the items that may be found in bacterial cytoplasm. Check All That Apply Water Nucleus Mitochondria Ribosomes Plasmids Bacterial chromosome Bacterial endospores Inclusion bodies Enzymes
Water Ribosomes Plasmids Bacterial chromosome Bacterial endospores Inclusion bodies Enzymes
Which of the following bacterial groups is/are described correctly? Multiple Choice a. Spirochetes - move by axial fibrils b. Actinomycetes - reproduce by fragmentation c. Nocardiae - form specialized dispersal cells on aerial mycelia d. Spirochetes - move by axial fibrils and Actinomycetes - reproduce by fragmentation e. Spirochetes - move by axial fibrils, Actinomycetes - reproduce by fragmentation, and Nocardiae - form specialized dispersal cells on aerial mycelia
a. Spirochetes - move by axial fibrils
The purpose of staining cells on a microscope slide is to ______. Multiple Choice observe motility secure them to the slide add contrast to see them better kill them enlarge the cells
add contrast to see them better
Viral spikes are used for Multiple Choice conjugation. lysogeny. replication of RNA. attachment to host cells.
attachment to host cells.
Basic dyes are Multiple Choice dyes such as India ink and nigrosin. attracted to the acidic surface of bacterial cells. used in negative staining. anionic. repelled by cells.
attracted to the acidic surface of bacterial cells. Correct
The bacterial flagellum moves Multiple Choice by rotation that is powered by ATP. by rotation that is powered by the proton motive force. in a wave-like fashion that is powered by ATP. in a wave-like fashion that is powered by the proton motive force. in a wave-like fashion that is powered by enzymes.
by rotation that is powered by the proton motive force.
The movement of bacteria either toward or away from a chemical stimulus is referred to as _______. Multiple Choice phototropism phototaxis hydrotaxis chemotaxis
chemotaxis
The Gram staining procedure is best described as a ______ staining technique. Multiple Choice selective simple negative differential
differential
Which of the following bacterial genera is/are described correctly? Multiple Choice a. Clostridium - spore-forming rod b. Corynebacterium - club-shape c. Vibrio - curved rod d. Clostridium - spore-forming rod and Corynebacterium - club-shape e. Clostridium - spore-forming rod, Corynebacterium - club-shape, and Vibrio - curved rod
e. Clostridium - spore-forming rod, Corynebacterium - club-shape, and Vibrio - curved rod
As a major component of gram-negative outer membranes, lipopolysaccharide can stimulate shock and fever and is referred to as ______. Multiple Choice endotoxin glycosphingolipid phospholipid exotoxin
endotoxin
Endospores are reproductive structures produced by multiple bacterial cell divisions, with one vegetative cell producing many endospores. True or False
false (Endospores are not reproductive structures. One vegetative cell will form one endospore. When the spore is released, the vegetative cell (sporangium) is lysed. When the endospore germinates, it will form one vegetative cell.)
C. diphtheriae produces a toxin that is really encoded by a lytic phage infecting this bacterium. True or False
false (False. It is lysogenized by the phage encoding this toxin; the phage is not lytic.)
The specimen preparation technique that is best for viewing cell motility is the ______. Multiple Choice negative stain hanging drop fixed, stained smear flagellar stain Gram stain
hanging drop
Scattering of peripheral light rays through the glass slide under very high magnification can be prevented by ______. Multiple Choice the ocular the cover slip immersion oil the condenser
immersion oil
All of the following pertain to the fluorescence microscope except Multiple Choice it is a type of compound microscope. it is used to diagnose certain infections. it requires the use of dyes like acridine or fluorescein. it requires an ultraviolet radiation source. it uses electrons to produce a specimen image.
it uses electrons to produce a specimen image
Magnification is achieved in a compound microscope through the initial magnification of the specimen by the _____ lens. This image is then projected to the _____ lens that will further magnify the specimen to form a virtual image received by the eye. Multiple Choice ocular; oil immersion ocular; objective scanning; objective objective; ocular
objective; ocular
The transfer of genes during bacterial conjugation involves rigid, tubular appendages called ______. Multiple Choice cilia sex pili flagella periplasmic flagella (axial filaments) fimbriae
sex pili
A microbiologist makes a fixed smear of bacterial cells and stains it with methylene blue. All cells appear blue under the oil immersion lens. This is an example of ______. Multiple Choice capsule staining simple staining using an acidic dye the acid-fast stain negative staining
simple staining
A spirochete moves in a screw-like manner that is mediated by axial fibrils located in the cell's periplasmic space. True or False
true
Fixed smears of specimens are required to perform the Gram stain or the endospore stain. True or False
true
Hot carbol fuchsin is the primary dye in the acid-fast stain. True or False
true
If you observe rod-shaped, pink cells on a slide that had just been Gram stained, you can assume that their cell envelope contains endotoxin. True or False
true
Mycoplasma pneumoniae lacks a cell wall and is termed pleomorphic. True or False
true
Spirillum is a genus of spiral-shaped bacteria that move by flagella. True or False
true
The bending of light rays as they pass from one medium to another is called refraction. True or False
true
Viruses are considered filterable because the cell-free portion of filtered infectious fluids could still transmit disease in experiments. True or False
true (Filtered infectious fluids considered 'cell free' could transmit disease, leading to the application of the term "filterable" in relation to viruses. )
The term used to describe a gently curved bacillus (rod) is ______. Multiple Choice coccobacillus streptobacillus vibrio spirochete
vibrio
