Micro bio practice test questions
Which of the following stains would best determine if a bacterium has a single cell membrane plus a very thick cell wall or if a bacterium has a very thin cell wall in between two cell membranes? Multiple Choice Endospore stain Gram-stain Capsule stain
Gram-stain
Some archaea have been observed to form tubelike structures with tiny grappling hooks at the ends. These tubelike structures are called _________. Multiple Choice cannulae pili flagella hami
Hami
Select all that are characteristics of transmission electron microscopes. Check All That Apply Highest practical magnification over 100,000 times Uses visible light for radiation source Contains glass lenses Uses electron beam for radiation source Switch objective lens to change magnification Adjust current to magnetic lenses to change magnification Highest practical magnification of 1,000 to 1,500 times
Highest practical magnification over 100,000 times Uses electron beam for radiation source Adjust current to magnetic lenses to change magnification
Which of the following experiments is used to identify new pathogens? Multiple Choice Koch postulates Pasteur's swan-neck experiment Endosymbiotic theory Stanley Miller experiment
Koch postulates
Approximate focal lengths for four different objective lenses are given below. Choose the lens that would provide the highest magnification. Multiple Choice Lens A: 1.3 mm Lens B: 40 mm Lens C: 4 mm Lens D: 17 mm
Lens A: 1.3 mm
Match each of the following archaeal cell envelope components with its biochemical composition. Pseudomurein Plasma membrane S-layer Lipid Protein Polysaccharide
Lipid Plasma membrane Protein S-layer Pseudomurein Polysaccharide
Which of the following is a component of the outer membrane in Gram-negative bacteria that results in septic shock upon entering the bloodstream? Multiple Choice Peptidoglycan Porin proteins Teichoic acids Lipopolysaccharide
Lipopolysaccharide
Order the objective lenses listed from the smallest to largest working distance that results when they are used. Multiple Choice Oil immersion; high power; low power Low power; high power; oil immersion Oil immersion; low power; high power High power; oil immersion; low power
Oil immersion; high power; low power
After performing a Gram stain of a mixed culture of Gram-positive and Gram-negative cells, you shout: "Oops, I forgot the iodine step!" What would you expect to see if you observed the slide under the microscope? Multiple Choice Purple Gram-positive and pink Gram-negative cells Pink Gram-positive and purple Gram-negative cells Colorless Gram-positive and pink Gram-negative cells Pink Gram-positive and pink Gram-negative cells
Pink Gram-positive and pink Gram-negative cells
Which of the following bacterial groups is/are described CORRECTLY? Multiple Choice Spirochetes - move by axial fibrils Actinomycetes - reproduce by fragmentation Nocardiae - form specialized dispersal cells on aerial mycelia Spirochetes - move by flagella movement Spirochetes - move by axial fibrils and Nocardiae-form specialized dispersal cells on aerial mycelia
Spirochetes - move by axial fibrils
A cell morphology unique to Archae is Rods in Chains Coccus Spiral Curved rods Square
Square
Choose the correct scientific name for a microbial species. Multiple Choice Staphylococcus aureus Streptococcus Pyogenes klebsiella Pneumoniae Escherichia Coli
Staphylococcus aureus
What microscope would be the best to use to view cell surface features of a specimen? Multiple Choice Scanning electron Fluorescence Phase-contrast Transmission electron
Scanning electron
Gliding motility in bacteria involves which of the following? Multiple Choice Specialized cell-surface proteins Slimy polysaccharides Flagella Specialized cell-surface proteins and slimy polysaccharides Specialized cell-surface proteins, flagella, and slimy polysaccharides
Specialized cell-surface proteins and slimy polysaccharides
Which of the following bacterial genera is/are described CORRECTLY? Multiple Choice Clostridium - club-shaped rod Corynebacterium - spore-forming rod Vibrio - curved rod Corynebacterium - spore-forming rod and Vibrio-curved rod Corynebacterium - spore-forming rod and Clostridium - club-shaped rod
Vibrio - curved rod
When observing flagella distribution patterns, bacteria with a single flagellum at each pole are called ________________ bacteria.
amphitrichous
Archaea with a plasma membrane composed of a tetraether monolayer would most likely be found __________. in the soil at a temperature of 90oC Correct in the mammalian gut at a pH of 2 in an anaerobic environment
at a temperature of 90oC
The scientific discipline known as _____________ involves using computers to analyze the genetic information obtained by molecular biologists in order to identify potential protein-coding genes, determine what they code for, and identify other regions of the genome that may have other important functions. Multiple Choice bioremediation bioinformatics immunology molecularization
bioinformatics
Considering the diversity of cell envelopes and their components in bacterial and archaeal cells, which of the following statements are correct? Check All That Apply All cell envelopes require a membrane. All cell envelopes require a layer external to the membrane. Cell envelope layers external to the membrane are composed of structural polysaccharides. A periplasm layer may be found in the cell envelopes of both Gram-positive bacteria and Gram-negative bacteria.
All cell envelopes require a membrane. A periplasm layer may be found in the cell envelopes of both Gram-positive bacteria and Gram-negative bacteria.
A microbe is discovered living in an extreme environment near a deep sea vent. The microorganism lacks a nucleus and peptidoglycan in its cell wall, but it does have unusual membrane lipids. This species is most likely a member of the Domain ________. Multiple Choice Eukarya Bacteria Archaea Animalia
Archaea
Gram-positive bacteria have flagella with four basal body rings, while those of Gram-negative bacteria have only two. True or False
False
The Gram stain can only be performed on cultures grown in liquid media. True or False
False
The focal length for a low power objective lens would be shorter than that for an oil immersion lens. True or False
False
Which of the following bacterial structures are most directly linked to swimming motility in chemotaxis? Multiple Choice Fimbriae Pili Flagella Capsule
Flagella
Which of the following microscopes typically uses dyes or antibodies? Multiple Choice Phase-contrast microscope Fluorescence microscope Electron microscope Atomic force microscope
Fluorescence microscope
Determining the DNA sequence of a microorganism's chromosome is the first step in the process of _________ analysis, a promising new field in microbiology.
Genomic
Which of the following advances best describes that today we may be experiencing a second golden age of microbiology? Multiple Choice Koch postulates Genomic testing Biochemical testing Light microscopy
Genomic testing
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 either a wave-like fashion or rotation that is powered by the proton motive force
by rotation that is powered by the proton motive force
Classify the following characteristics as describing pseudomurein or peptidoglycan.
c
An external structure unique to archaea are the __________. Multiple Choice cannulae Correct flagella fimbriae pili
cannulae
The Gram stain of a bacterial cell is based on the chemical properties of its ________. Multiple Choice cell membrane cell wall capsule ribosomes nucleus
cell wall
The spore layer containing peptidoglycan is the ______. Multiple Choice inner membrane cortex germ cell wall sporangium protein coat
cortex
The proper sequence of reagents in the Gram stain procedure is Multiple Choice iodine, ethanol, safranin, crystal violet. safranin, crystal violet, ethanol, iodine. crystal violet, ethanol, iodine, safranin. crystal violet, iodine, ethanol, safranin. ethanol, iodine, crystal violet, safranin.
crystal violet, iodine, ethanol, safranin.
As the magnification on a bright-field microscope increases, the amount of light that reaches the eye ________. Multiple Choice decreases increases doesn't change
decreases
Germination is one process by which bacterial cells can reproduce. True or False
fALSE
Capsules and slime layers are networks of polysaccharides that can extend from the bacterial surface. Both capsules and slime layers can be encompassed by the general term _________________.
glycocalyx
A(n) ________ microscope uses lenses made of glass to focus light onto a specimen.
light
A(n) ________ microscope keeps an object in focus when the objective lens is changed. Multiple Choice optically constant focally constant parfocal equifocal
parfocal
In the Gram-positive bacterial cell wall, the tetrapeptides that extend from the peptidoglycan layers are linked by ______. Multiple Choice a direct peptide bond carbohydrate interbridges fatty acid interbridges peptide interbridges
peptide interbridges
Carl Woese distinguished between the members of the Archaea and the Bacteria using studies of their ________. Multiple Choice ribosomal RNA messenger RNA DNA transfer RNA
ribosomal RNA
A lens with a _____ focal length should have a greater magnification. Multiple Choice short long doesn't matter
short
Spore formation is initiated when there is a scarcity of nutrients. True or False
tRUE
Checked all of the structures associated with our Archael cells Cannulae Flagella 80 S ribosomes Hami Nucleus Pili
Cannulae Flagella Hami Pili
Match the state of Gram-negative and Gram-positive bacteria to the stain/reagent used in each step of the Gram stain procedure. After this Gram stain step, Gram-positive bacteria are purple and Gram-negative bacteria are red or pink. 1) After this Gram stain step, purple Gram-positive bacteria and purple Gram-negative bacteria remain purple. 2) After this Gram stain, both Gram-positive bacteria and Gram-negative bacteria are purple. 3) After this Gram stain step, Gram-positive bacteria are purple and Gram-negative bacteria are colorless. 4) Crystal Violet Alcohol Decolorizer Safranin Gram's Iodine
Crystal Violet 3) Alcohol Decolorizer 4) Safranin 1) Gram's Iodine 2)
Which of the following cocci cell arrangements is/are described CORRECTLY? Multiple Choice Staphylococci - Chains of spherical cells Streptococci - Grape-like clusters of spherical cells Diplococci - Pairs of spherical cells Staphylococci - Chains of spherical cells and streptococci - Grape-like clusters of spherical cells Staphylococci - Chains of spherical cells, streptococci - Grape-like clusters of spherical cells, and diplococci - Pairs of spherical cells
Diplococci - Pairs of spherical cells
Clostridium botulinum, which produces a toxin that causes botulism, is a major concern of the food industry due to its production of an extremely heat-resistant ________.
Endospore
The three domain system, comprising the bacteria, the _________, and the archaea, was devised in the 1970s by Carl Woese.
Eukarya
After performing a Gram stain of a mixed culture of Gram-positive and Gram-negative cells, you shout: "Oops, I forgot the iodine step!" What would you expect to see if you observed the slide under the microscope? Multiple Choice Purple Gram-positive and pink Gram-negative cells Pink Gram-positive and purple Gram-negative cells Colorless Gram-positive and pink Gram-negative cells Pink Gram-positive and pink Gram-negative cells Colorless Gram-positive and colorless Gram-negative cells
Pink Gram-positive and pink Gram-negative cells
Check all of the following that showcases how microbes can be used by people. Check All That Apply Production of breads Production of cheeses Production of antibiotics Production of vitamins Production of enzymes used for many different industrial applications
Production of breads Production of cheeses Production of antibiotics Production of vitamins Production of enzymes used for many different industrial applications
To determine the relatedness of a new species of microbe to other species, genes that encode small subunit ____ molecules are compared to determine the number of differences in the sequence. Multiple Choice DNA RNA proteins lipids
RNA
Which statement 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 filament extends out of the cell. 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.
Check All That Apply The hydrocarbon chains in this lipid are attached to glycerol by an ester linkage (indicated by the letter A). The hydrocarbon chains in this lipid are attached to glycerol by an ether linkage (indicated by the letter A). The hydrocarbon chain (indicated by the letter B) is best described as linear and unsaturated. The hydrocarbon chain (indicated by the letter B) is best described as branched. This structure most likely derives from a bacterium. This structure most likely derives from an archaeon.
The hydrocarbon chains in this lipid are attached to glycerol by an ester linkage (indicated by the letter A). The hydrocarbon chain (indicated by the letter B) is best described as linear and unsaturated. This structure most likely derives from a bacterium.
How does the addition of immersion oil provide better magnification than a high power lens alone? Multiple Choice The immersion oil has a higher refractive index than the glass composed in slides or cover slips and thus bends more light rays, allowing the lens to collect more light. The immersion oil has a lower refractive index than the glass composed in slides or cover slips and thus bends more light rays, allowing the lens to collect more light. The immersion oil has the same refractive index as glass; by placing a drop of oil between the glass slide and the lens, this eliminates two refractive surfaces. The immersion oil used has a higher refractive index than the objective lens used, thus causing more light rays to be bent.
The immersion oil has the same refractive index as glass; by placing a drop of oil between the glass slide and the lens, this eliminates two refractive surfaces.
Which microscope would be the best to use to constituents within a cell? Multiple Choice Transmission electron microscope Light microscope Dark-field microscope Scanning electron microscope
Transmission electron microscope
Acetone can be used as the decolorizer in the Gram stain procedure. True or False
True
Mycoplasma pneumoniae lacks a cell wall and are pleomorphic in shape. True or False
True
Spirillum is a genus of spiral-shaped bacteria that move by flagella. True or False
True
Spirochetes move in a screw-like manner that is mediated by bundles of flagella located in the cell's periplasmic space. True or False
True
Check all the following that can affect the resolution of a bright-field microscope. Check All That Apply Wavelength of lightWavelength of light Type of specimenType of specimen Quality of lensesQuality of lenses MagnificationMagnification
Wavelength of lightWavelength of light Quality of lensesQuality of lenses MagnificationMagnification
After conducting the Gram stain on a mixed culture containing Gram-positive rods and Gram-negative cocci, all the cells were purple in color. This was most likely because ________. Multiple Choice the cells were not decolorized enough with alcohol or acetone the cells were decolorized too much with alcohol or acetone the Gram-negative cells did not take up the counterstain the Gram-positive cells did not take up the counterstain
the cells were not decolorized enough with alcohol or acetone
The first of Koch's postulates is Multiple Choice animals infected with the isolated microorganism must develop the same disease. the same microorganisms must be isolated from the diseased animal host. the suspected microorganisms must be isolated and grown in a pure culture. the microorganism must be present in every case of the disease but absent from healthy organisms.
the microorganism must be present in every case of the disease but absent from healthy organisms