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Microbial Exam 1 Oldies Questions Compilation

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Microbial Exam 1 Oldies Questions Compilation

Microbial Exam 1 Oldies Questions Compilation

Frage 1 von 107

1

A substance found in the plasma membrane of eukaryotic cells but not the plasma membrane of most prokaryotic cells is ______.

Wähle eine der folgenden:

  • cholesterol

  • phospholipids

  • proteins

  • phospholipids and proteins

  • cholesterol, phospholipids, and proteins

Erklärung

Frage 2 von 107

1

An acidophile is an organism that ____.

Wähle eine der folgenden:

  • ferments glucose to lactic acid

  • requires organic acids for growth

  • grows at high salt concentrations

  • ferments sugars to acids

  • tolerate exposure to low pH values without being killed

Erklärung

Frage 3 von 107

1

Bacteria that use O2 for aerobic respiration when it is present, but also grow in its absence by fermenting substrates are called ____.

Wähle eine der folgenden:

  • obligate aerobes

  • facultative anaerobes

  • microaerophile

  • aerotolerant anaerobes

  • obligate anaerobes

Erklärung

Frage 4 von 107

1

Bacteria that lack cell walls readily lyse in _____ solution.

Wähle eine der folgenden:

  • hypotonic

  • hypertonic

  • isotonic

  • hypertonic and hypotonic

  • none of the above

Erklärung

Frage 5 von 107

1

Bacteria in the logarithmic phase of growth ______.

Wähle eine der folgenden:

  • double at a constant rate called the generation time

  • increase 10-fold in number with each generation

  • form new cells at the same rate that old cells die

  • - double at a constant rate called the generation time
    - form new cells at the same rate that old cells die

  • none of the above

Erklärung

Frage 6 von 107

1

Capsules are important virulence factors for bacteria because they ____.

Wähle eine der folgenden:

  • are antiphagocytic factors

  • can mediate the attachment of bacteria to surfaces (including host surfaces)

  • are endotoxins

  • - are antiphagocytic factors
    - can mediate the attachment of bacteria to surfaces (including host surfaces)

  • - are antiphagocytic factors
    - are endotoxins

Erklärung

Frage 7 von 107

1

Chains of cocci are called _______.

Wähle eine der folgenden:

  • streptococci

  • diplococci

  • staphylococci

  • sarcinae

  • coccobacilli

Erklärung

Frage 8 von 107

1

Ignatz Semmelweis discovered that the incidence of peurperal (childbirth) fever could be lowered dramatically by ______.

Wähle eine der folgenden:

  • penicillin

  • hand and instrument washing in chlorinated lime

  • prayer

  • having doctors deliver babies instead of midwives

  • none of the above

Erklärung

Frage 9 von 107

1

In glycolysis, one molecule of glucose is converted into _____.

Wähle eine der folgenden:

  • CO2 and H2O

  • citrate

  • ethanol and CO2

  • glycogen

  • two molecules of pyruvate

Erklärung

Frage 10 von 107

1

Media that are specifically designed to grow anaerobic bacteria are called ____ media.

Wähle eine der folgenden:

  • reducing

  • differential

  • selective

  • chemically defined

  • enrichment

Erklärung

Frage 11 von 107

1

Microorganisms that grow only at temperatures between -10 and 20 C are called _____.

Wähle eine der folgenden:

  • thermophiles

  • mesophiles

  • psychrophiles

  • psychrotrophs

  • extreme thermophiles

Erklärung

Frage 12 von 107

1

Negative stains _______.

Wähle eine der folgenden:

  • stain the background, not the cell

  • are used to detect capsules

  • stain gram-negative bacteria but not gram-positive bacteria

  • - stain the background, not the cell
    - are used to detect capsules

  • - stain the background, not the cell
    - stain gram-negative bacteria but not gram-positive bacteria

Erklärung

Frage 13 von 107

1

Siderophores are _______.

Wähle eine der folgenden:

  • toxic oxygen metabolites that form in cells

  • compounds secreted by bacteria that solubilize ferric ions

  • organic growth factors that have to be added to bacterial media

  • electron transport carriers in bacteria

  • none of the above

Erklärung

Frage 14 von 107

1

The cell wall component that protects bacteria against lysis by osmotic pressure is _________.

Wähle eine der folgenden:

  • peptidoglycan

  • teichoic acid

  • lipopolysaccharide

  • phospholipid

  • porins

Erklärung

Frage 15 von 107

1

The conversion of glucose to lactic acid by oral streptococci and lactobacilli _________.

Wähle eine der folgenden:

  • produces only 2 molecules of ATP for each molecule of glucose degraded

  • is an important event in the formation of dental caries

  • is an example of fermentation

  • - produces only 2 molecules of ATP for each molecule of glucose degraded
    - is an example of fermentation

  • - produces only 2 molecules of ATP for each molecule of glucose degraded
    - is an important event in the formation of dental caries
    - is an example of fermentation

Erklärung

Frage 16 von 107

1

The outer membrane of gram-negative bacteria contains ________.

Wähle eine der folgenden:

  • peptidoglycan

  • lipopolysaccharide

  • porins

  • - lipopolysaccharide
    - porins

  • - peptidoglycan
    - lipopolysaccharide
    - porins

Erklärung

Frage 17 von 107

1

The primary function of the cytoplasmic membrane in prokaryotes is to ________.

Wähle eine der folgenden:

  • act as a selective barrier that controls the entry and exit of molecules into the cell

  • protect bacterial cells from osmotic lysis

  • act as an adhesin

  • synthesize proteins

  • none of the above

Erklärung

Frage 18 von 107

1

The total number of viable bacteria in 1 ml of a broth culture can be determined by ______.

Wähle eine der folgenden:

  • the streak plate technique

  • a standard plate count

  • a direct microscope count

  • - a standard plate count
    - a direct microscope count

  • - the streak plate technique
    - a standard plate count
    - a direct microscope count

Erklärung

Frage 19 von 107

1

The degree of relatedness between two microorganisms can best be determined by ________.

Wähle eine der folgenden:

  • biochemical tests

  • morphological features

  • DNA hybridization

  • differential staining

  • DNA base composition

Erklärung

Frage 20 von 107

1

The enzyme that converts H2O2 into H2O and O2 is called _____.

Wähle eine der folgenden:

  • lysozyme

  • superoxide dismutase

  • catalase

  • peroxidase

  • oxygenase

Erklärung

Frage 21 von 107

1

The newly published Bergey's Manual of Systemic Bacteriology, 2nd Edition classifies prokaryotes into taxonomic units primarily based upon _____.

Wähle eine der folgenden:

  • morphological criteria

  • biochemical tests

  • rRNA nucleotide sequence

  • - morphological criteria
    - biochemical tests

Erklärung

Frage 22 von 107

1

The Three Domain System for the classification of microorganisms places _____.

Wähle eine der folgenden:

  • prokaryotes into two domains called Protista and Bacteria

  • domains over Kingdoms

  • all eukaryotic cells into a single domain called Eukarya

  • - domains over kingdoms
    - all eukaryotic cells into a single domain called Eukarya

  • - prokaryotes into two domains called Protista and Bacteria
    - domains over kingdoms
    - all eukaryotic cells into a single domain called Eukarya

Erklärung

Frage 23 von 107

1

The transfer of DNA from one bacterium to another by a bacteriophage is called ________.

Wähle eine der folgenden:

  • conjugation

  • transformation

  • transportation

  • transduction

  • lysogeny

Erklärung

Frage 24 von 107

1

The pour-plate technique differs from the spread-plate technique (for doing a standard plate count) in that ______.

Wähle eine der folgenden:

  • serial dilutions are prepared in the pour-plate method but not the spread-plate method

  • colonies form in the agar and on the surface in the pour-plate method, but only on the surface with the spread plate method

  • the bacterial sample is mixed into molten agar in the pour plate method, but are spread over the surface of hardened agar in the spread plate method

  • - colonies form in the agar and on the surface in the pour-plate method, but only on the surface with the spread plate method
    - the bacterial sample is mixed into molten agar in the pour plate method, but are spread over the surface of hardened agar in the spread plate method

  • - serial dilutions are prepared in the pour-plate method but not the spread-plate method
    - colonies form in the agar and on the surface in the pour-plate method, but only on the surface with the spread plate method
    - the bacterial sample is mixed into molten agar in the pour plate method, but are spread over the surface of hardened agar in the spread plate method

Erklärung

Frage 25 von 107

1

The process of destroying all microbial life forms is called ______.

Wähle eine der folgenden:

  • sterilization

  • antisepsis

  • disinfection

  • sanitization

  • bacteriostasis

Erklärung

Frage 26 von 107

1

Which of the following statements about facilitated transport is (are) true?

Wähle eine der folgenden:

  • it requires ATP or other high energy compound

  • it requires a transporter protein

  • It accumulates substrates to higher concentration inside a cell than outside a cell

  • - it requires a transporter protein
    - It accumulates substrates to higher concentration inside a cell than outside a cell

  • - it requires ATP or other high energy compound
    - it requires a transporter protein
    - It accumulates substrates to higher concentration inside a cell than outside a cell

Erklärung

Frage 27 von 107

1

Which of the following statements about endospores is FALSE?

Wähle eine der folgenden:

  • they are reproductive structures

  • they are much more resistant to killing than vegetative cells

  • they can germinate and cause food spoilage or disease

  • Bacillus and Clostridium are the only medically important bacteria to produce endospores

  • they can survive in soil for a hundred years or more

Erklärung

Frage 28 von 107

1

Which of the following statements about eukaryotic ribosomes is (are) true?

Wähle eine der folgenden:

  • they are smaller than prokaryotic ribosomes

  • they can bind to the endoplasmic reticulum

  • they are the sites of oxidative phosphorylation in eukaryotic cells

  • - they are smaller than prokaryotic ribosomes
    - they can bind to the endoplasmic reticulum

  • - they are smaller than prokaryotic ribosomes
    - they are the sites of oxidative phosphorylation in eukaryotic cells

Erklärung

Frage 29 von 107

1

Which of the following statements best explains why gram-negative bacteria are more resistant than gram-positive bacteria to most antibiotics and detergents?

Wähle eine der folgenden:

  • gram-negative bacteria have less peptidoglycan in their cell wall

  • gram-positive bacteria have teichoic acids in their cell wall

  • antibiotics and detergents often have difficulty penetrating the outer membrane of gram-negative bacteria

  • gram-negative bacteria have a different cytoplasmic membrane structure

  • none of the above

Erklärung

Frage 30 von 107

1

Which of the following statements about eukaryotic cells is FALSE? If none are false, choose "none of the above."

Wähle eine der folgenden:

  • they may be motile by either flagella or cilia

  • all eukaryotic cells have cell walls

  • their nuclear membrane has pores in it

  • the nuclear membrane of eukaryotes is contiguous with the endoplasmic reticulum

  • none of the above

Erklärung

Frage 31 von 107

1

Which of the following statements about microbial growth is FALSE?

Wähle eine der folgenden:

  • most microorganisms grow very rapidly

  • growth is determined by the size of the individual cells

  • bacteria grow by binary fission

  • unchecked microbial growth can cause food spoilage and disease

  • microorganisms can form very large populations of cells

Erklärung

Frage 32 von 107

1

Which of the following statements about porins is true?

Wähle eine der folgenden:

  • they form pores (channels) in the outer membrane of gram-negative bacteria

  • they are found in gram-positive bacteria

  • they allow nutrients to pass through the cytoplasmic membrane of eukaryotes

  • they are membrane-bound organelles found in eukaryotic cells

  • none of the above

Erklärung

Frage 33 von 107

1

Which of the following statements about lipopolysaccharides is FALSE?

Wähle eine der folgenden:

  • they are also called endotoxin

  • they cause fever

  • the O-specific polysaccharide is the toxic component

  • they consist of three disscernable regions called lipid A, core polysaccharide, and O-specific polysaccharide

  • they are inactivated by autoclaving

Erklärung

Frage 34 von 107

1

Which of the following statements about peptidoglycan is FALSE?

Wähle eine der folgenden:

  • it is present in gram-negative bacteria

  • it is present in gram-positive bacteria

  • it gives bacterial cells their shape and rigidity

  • it completely surrounds bacterial cells

  • it is a large polymer composed solely of amino acids

Erklärung

Frage 35 von 107

1

Which of the following is NOT a mechanism by which bacteria exchange genetic material?

Wähle eine der folgenden:

  • conjugation

  • transformation

  • transduction

  • crossing over

Erklärung

Frage 36 von 107

1

Transcription is _________.

Wähle eine der folgenden:

  • the process of protein synthesis

  • occurs on ribosomes

  • - the process of protein synthesis
    -occurs on ribosomes

  • none of the above

Erklärung

Frage 37 von 107

1

Which of the following are eukaryotes?

Wähle eine der folgenden:

  • Bacteria

  • Archaea

  • Fungi

  • Viruses

  • None of the above

Erklärung

Frage 38 von 107

1

Which of the following statements about fermentations is FALSE?

Wähle eine der folgenden:

  • they occur in the absence of oxygen

  • they use an organic molecule as the final electron acceptor

  • they release energy from a sugar or other organic molecule

  • they are considerable less efficient than aerobic respiration

  • they require and electron transport chain

Erklärung

Frage 39 von 107

1

Which of the following statements about fimbriae is FALSE?

Wähle eine der folgenden:

  • they are thin, hairlike filaments

  • they can act as adhesins

  • they give bacterial cells motility

  • there may be as many as 100-200 fimbriae per cell

  • they are important virulence factors for some pathogenic bacteria

Erklärung

Frage 40 von 107

1

Which of the following statements about prokaryotic cells is (are) true?

Wähle eine der folgenden:

  • they have membrane bound organelles in their cytoplasm

  • their nucleus lacks a membrane and is in direct contact with the cytoplasm

  • their cytoplasm has a microtubule cytoskeleton

  • - they have membrane bound organelles in their cytoplasm
    - their nucleus lacks a membrane and is in direct contact with the cytoplasm

  • - they have membrane bound organelles in their cytoplasm
    - their cytoplasm has a microtubule cytoskeleton

Erklärung

Frage 41 von 107

1

Which of the following microscopes has the most resolving power and gives the highest magnification?

Wähle eine der folgenden:

  • brightfield microscope

  • darkfield microscope

  • phase-contrast microscope

  • fluorescence microscope

  • transmission electron microscope

Erklärung

Frage 42 von 107

1

Which of the following is the correct order of the four steps in the Gram stain?

Wähle eine der folgenden:

  • 1) safranin 2) iodine 3) alcohol 4) crystal violet

  • 1) iodine 2) safranin 3) alcohol 4) crystal violet

  • 1) crystal violet 2) iodine 3) alcohol 4) safranin

  • 1) crystal violet 2) alcohol 3) iodine 4) safranin

  • 1) alcohol 2) safranin 3) iodine 4) crystal violet

Erklärung

Frage 43 von 107

1

Which of the following statements about a typical cytoplasmic membrane under normal physiological conditions is NOT true?

Wähle eine der folgenden:

  • If you believe none of the other 3 choices is a correct answer to the question, choose this choice

  • Membrane proteins float in the lipids of a cytoplasmic membrane under normal conditions

  • The lipids in a cytoplasmic membrane typically have the consistency of a light oil

  • Membrane proteins can freely flip-flop from one layer (leaflet) of a membrane to the other

Erklärung

Frage 44 von 107

1

The individual microbial species in a mixed sample of microbes can be separated from each other and grown in pure culture by ______.

Wähle eine der folgenden:

  • plating serial dilution of the sample on agar media

  • the streak plate technique

  • none of the above

  • - plating serial dilution of the sample on agar media
    -the streak plate technique

Erklärung

Frage 45 von 107

1

The number of cells in an actively growing microbial population doubles with each succeeding generation. A doubling of cell number with each generation is commonly called arithmetic growth.

Wähle eine der folgenden:

  • The first statement is false; the second statement is false

  • The first statement is true; the second statement is true

  • The first statement is true; the second statement is false

  • The first statement is false; the second statement is true

Erklärung

Frage 46 von 107

1

Which of the following is NOT a possible reason for the occurrence of a stationary phase in a bacterial growth curve?

Wähle eine der folgenden:

  • none of the above

  • accumulation of waste products in the growth medium

  • depletion of nutrients in the growth medium

  • the generation time of the dividing organisms

  • a drop in the pH of the growth medium

Erklärung

Frage 47 von 107

1

The cytoskeleton of prokaryotic cells is _______.

Wähle eine der folgenden:

  • none of the above

  • composed of microtubules

  • responsible for prokaryotic cytoplasmic streaming

  • an extensive network of filaments that runs throughout the cytoplasm of the cell

Erklärung

Frage 48 von 107

1

Which of the following microbes produces a slime layer that allows it to colonize devices implanted in skin such as a catheter?

Wähle eine der folgenden:

  • mycobacteria

  • Bacillus species

  • Streptococci

  • Staphylococci

Erklärung

Frage 49 von 107

1

The term aciduric means that a microbe _____.

Wähle eine der folgenden:

  • converts organic acids into CO2 and H2O

  • survives exposure to low pH without being killed

  • grows on amino acids instead of sugars

  • ferments sugars to acids

Erklärung

Frage 50 von 107

1

Which of the following statements about prokaryotic flagella is true?

Wähle eine der folgenden:

  • none of the above

  • they are composed of 3 parts: a long filament, a hook, and a basal body

  • their primary function is to mediate the attachment of prokaryotic cells to other cells or surfaces

  • they generate motion by a whip-like or wave motion

Erklärung

Frage 51 von 107

1

The theory of spontaneous generation was finally disproven once and for all by _________.

Wähle eine der folgenden:

  • Francesco Redi

  • Paul Ehrlich

  • Robert Kock

  • Louis Pasteur

  • Joseph Lister

Erklärung

Frage 52 von 107

1

Which of the following statements best explains why a cell would use a Na+ ion-glucose symporter to transport glucose into a cell?

Wähle eine der folgenden:

  • none of the above

  • the symporter is used to equalize the concentration of glucose inside and outside the cell

  • the symporter is used to transport glucose into a cell that has a higher concentration of glucose inside the cell than outside the cell

  • The symporter is used to transport glucose into a cell that has a lower concentration of glucose inside the cell than there is outside the cell

Erklärung

Frage 53 von 107

1

The component of the gram-negative outer cell wall membrane makes it a rigid membrane is:

Wähle eine der folgenden:

  • phosphoglyceride lipids

  • porins

  • the O-specific polysaccharide chain

  • the lipoprotein

  • lipid A

Erklärung

Frage 54 von 107

1

When glucose is fermented to lactic acid by a microbe, most of the original energy (calories) in the glucose molecule is _____.

Wähle eine der folgenden:

  • transferred to NADH

  • lost as heat

  • left in the lactic acid molecules

  • converted into ATP

Erklärung

Frage 55 von 107

1

Viable (standard) plate counts are done by _______.

Wähle eine der folgenden:

  • none of the above

  • making serial 1/10 dilutions of a bacterial sample and plating a known aliquot of each dilution on an agar growth medium

  • streaking the bacterial sample on a microbial growth medium

  • counting the number of cells in a known dilution of a bacterial sample using a microscope and a Petroff-Hauser counter

Erklärung

Frage 56 von 107

1

Transmission electron microscopes _______.

Wähle eine der folgenden:

  • are used to view the three dimensional structure of individual proteins and other macromolecules

  • have a higher magnification than light microscopes

  • none of the above

  • - are used to view the three dimensional structure of individual proteins and other macromolecules
    - have a higher magnification than light microscopes

Erklärung

Frage 57 von 107

1

Which of the following is the least toxic form of oxygen?

Wähle eine der folgenden:

  • molecular oxygen

  • singlet oxygen

  • peroxide anion

  • superoxide anion

  • hydroxyl free radical

Erklärung

Frage 58 von 107

1

The chances of isolating a pathogen that is present in small numbers from a sample that contains a large total number of microbes and many different microbial species can be greatly increased by using a ____.

Wähle eine der folgenden:

  • defined culture medium

  • complex culture medium

  • selective culture medium

  • reducing culture medium

  • candle jar

Erklärung

Frage 59 von 107

1

Which of the following statements about preserving food by freezing is true?

Wähle eine der folgenden:

  • it preserves food by its low temperature and making liquid water unavailable to the microbial cells

  • it kills all of the vegetative microbial cells in food

  • none of the above

  • - it preserves food by its low temperature and making liquid water unavailable to the microbial cells
    - it kills all of the vegetative microbial cells in food

Erklärung

Frage 60 von 107

1

The basic structure of most cytoplasmic membranes is a lipid bilayer that contains embedded proteins. The embedded proteins in a cytoplasmic membrane are the driving force for formation of the membrane.

Wähle eine der folgenden:

  • The first statement is false; the second statement is false

  • The first statement is true; the second statement is true

  • The first statement is true; the second statement is false

  • The first statement is false; the second statement is true

Erklärung

Frage 61 von 107

1

Which of the following stains is commonly used to detect the presence of a capsule around a microbe?

Wähle eine der folgenden:

  • negative stain

  • endospore stain

  • acid-fast stain

  • gram stain

Erklärung

Frage 62 von 107

1

The process of sporulation produces 1 endospore from a bacterial cell. Most pathogenic bacteria produce endospores when exposed to harsh conditions.

Wähle eine der folgenden:

  • The first statement is false; the second statement is false

  • The first statement is true; the second statement is true

  • The first statement is true; the second statement is false

  • The first statement is false; the second statement is true

Erklärung

Frage 63 von 107

1

Which of the following statements is true of the prokaryotes?

Wähle eine der folgenden:

  • none of the above

  • their genetic material is surrounded by a double membrane

  • They lack or have a simple cytoskeleton in their cytoplasm

  • They have specialized membrane-bound organelles in their cytoplasm

Erklärung

Frage 64 von 107

1

The conditions for historical pasteurization are _________.

Wähle eine der folgenden:

  • 75 C for 15 seconds

  • 100 C for 30 minutes at atmospheric pressure

  • 121 C for 15 minutes at 15 psi of pressure

  • 63 C for 30 minutes

Erklärung

Frage 65 von 107

1

Which of the following eukaryotic organelles contain a circular molecule of DNA and prokaryotic ribosomes?

Wähle eine der folgenden:

  • proteosomes

  • the Golgi apparatus

  • the endoplasmic reticulum

  • mitochondria

  • lysosomes

Erklärung

Frage 66 von 107

1

The endoplasmic reticulum of eukaryotic cells _________.

Wähle eine der folgenden:

  • none of the above

  • functions as a transport network for newly synthesized proteins

  • is continuous with the nuclear membrane

  • often has ribosomes bound to it

Erklärung

Frage 67 von 107

1

Which of the following is NOT a function of the cytoskeleton in eukaryotic cells?

Wähle eine der folgenden:

  • none of the above

  • it enables cytoplasmic streaming and the movement of organelles in cytoplasm

  • it anchors cytoplasmic organelles

  • it carries out the degradation of old and defective proteins in the cytoplasm

Erklärung

Frage 68 von 107

1

Teichuronic acids are:

Wähle eine der folgenden:

  • none of the above

  • produced by gram-positive bacteria when they are grown in phosphate-deficient media

  • also called the O-specific antigen

  • a component of lipopolysaccharides

Erklärung

Frage 69 von 107

1

Streptococci divide ______.

Wähle eine der folgenden:

  • in three different planes at right angles to each other

  • in two different planes at right angles to each other

  • in a single plane

  • randomly in any plane

Erklärung

Frage 70 von 107

1

the formation of phosphoenolpyruvate by glycolysis and the transfer of its phosphate group to ADP is an example of _________.

Wähle eine der folgenden:

  • dephosphorylation

  • substrate level phosphorylation

  • photophosphorylation

  • oxidative phosphorylation

Erklärung

Frage 71 von 107

1

Reducing media are used to grow ________.

Wähle eine der folgenden:

  • microaerophilic microbes

  • obligate anaerobes

  • chemoautotrophs

  • capnophilic microbes

Erklärung

Frage 72 von 107

1

Protozoa historically ___________.

Wähle eine der folgenden:

  • none of the above

  • are single celled organisms

  • have a prokaryotic cell structure

  • carry out photosynthesis

Erklärung

Frage 73 von 107

1

The Shaeffer-Fulton endospore stain is useful in the identification of _________.

Wähle eine der folgenden:

  • Mycobacterium species

  • Clostridium species

  • Bacillus species

  • - Clostridium species
    - Bacillus species

  • - Mycobacterium species
    - Clostridium species
    - Bacillus species

Erklärung

Frage 74 von 107

1

Peptidoglycan is __________________.

Wähle eine der folgenden:

  • composed of long polysaccharide chains cross-linked by amino acids

  • found only in gram-positive bacteria

  • none of the above

  • - composed of long polysaccharide chains cross-linked by amino acids
    - found only in gram-positive bacteria

Erklärung

Frage 75 von 107

1

Motile bacteria have the ability to detect and respond to a concentration gradient of a chemoattractant in their growth environment. Motile bacteria swim in a straight line when they rotate their flagella counterclockwise.

Wähle eine der folgenden:

  • The first statement is false; the second statement is false

  • The first statement is true; the second statement is true

  • The first statement is true; the second statement is false

  • The first statement is false; the second statement is true

Erklärung

Frage 76 von 107

1

Passive transport _________.

Wähle eine der folgenden:

  • none of the above

  • occurs only in prokaryotic cells

  • requires ATP

  • can move a substance across a membrane against a concentration gradient

Erklärung

Frage 77 von 107

1

A fastidious microbe is a microbe that ________.

Wähle eine der folgenden:

  • requires elevated levels of CO2 in order to grow

  • does not produce a bad odor when it is grown in culture

  • has special nutrient requirements

  • cannot be grown on artificial media

Erklärung

Frage 78 von 107

1

Microbes are ecologically important because they _______.

Wähle eine der folgenden:

  • none of the above

  • are the basis for the food chain in the oceans

  • recycle bound vital elements to a form that can be used again

  • produce most of the oxygen in the atmosphere

Erklärung

Frage 79 von 107

1

Long, straight, hair-like appendages on the surface of bacterial cells that are not involved in motility are called ______.

Wähle eine der folgenden:

  • axial filaments

  • microfilaments

  • fimbriae

  • microtubules

  • cilia

Erklärung

Frage 80 von 107

1

An obligate anaerobe produces adequate or high levels of __________.

Wähle eine der folgenden:

  • none of the above

  • peroxidase

  • catalase

  • superoxide dismutase

Erklärung

Frage 81 von 107

1

Indirect methods for measuring microbial growth include all of the following EXCEPT ___________.

Wähle eine der folgenden:

  • none of the above

  • measuring dry weight

  • measuring turbidity

  • membrane filtration followed by culture of the filter on microbial media

Erklärung

Frage 82 von 107

1

Bacteria grow by a simple process called binary fission. The generation time for microbial cells is usually 2 or 3 times longer than the generation time for eukaryotic cells.

Wähle eine der folgenden:

  • The first statement is false; the second statement is false.

  • The first statement is true; the second statement is true.

  • The first statement is true; the second statement is false.

  • The first statement is false; the second statement is true.

Erklärung

Frage 83 von 107

1

Eukaryotic flagella _______.

Wähle eine der folgenden:

  • generate motion by rotating like a turbine

  • are long cytoplasmic projections that contain microtubules

  • none of the above

  • - generate motion by rotating like a turbine
    - are long cytoplasmic projections that contain microtubules

Erklärung

Frage 84 von 107

1

Cells maintain an electrical gradient of -70 mV across their cytoplasmic membrane by selectively maintaining a high concentration of _____ in their cytoplasm and by having protein channels in their cytoplasmic membrane that are freely permeable to _____.

Wähle eine der folgenden:

  • Na+ ions / Na+ ions

  • K+ ions / Na+ ions

  • K+ ions / K+ ions

  • Na+ ions / K+ ions

Erklärung

Frage 85 von 107

1

Bacteriostasis means that _______.

Wähle eine der folgenden:

  • bacterial growth is inhibited, but the bacteria are not killed

  • bacteria are growing (multiplying)

  • all bacteria are killed

  • the number of live microbes have been reduced to a safe level

Erklärung

Frage 86 von 107

1

Immunofluorescence tests require ___________.

Wähle eine der folgenden:

  • a phase contrast microscope

  • specific antibodies to a microbe

  • none of the above

  • - specific antibodies to a microbe
    - a phase contrast microscope

Erklärung

Frage 87 von 107

1

Bacterial cells that are treated with penicillin are killed by _________.

Wähle eine der folgenden:

  • none of the above

  • hypotonic lysis

  • inhibition of DNA synthesis

  • inhibition of protein synthesis

Erklärung

Frage 88 von 107

1

All of the following statements are true about all eukaryotic cells EXCEPT one. Which one is the exception?

Wähle eine der folgenden:

  • none of the above

  • they have a complex cytoskeleton

  • they have membrane-bound organelles in their cytoplasm

  • they have membrane around their nucleus

  • they have a cell wall

Erklärung

Frage 89 von 107

1

Lipid enveloped viruses are usually more resistant to inactivation (killing) by most antimicrobial agents than naked viruses. The presence of organic matter, grease and/or dirt can interfere with the killing action of an antimicrobial agent.

Wähle eine der folgenden:

  • The first sentence is true; the second sentence is false

  • The first sentence is false; the second sentence is true

  • The first sentence is false; the second sentence is false

  • The first sentence is true; the second sentence is true

Erklärung

Frage 90 von 107

1

All of the following are required for a cell to break down glucose by aerobic respiration, EXCEPT for ________.

Wähle eine der folgenden:

  • peroxisomes

  • oxygen

  • the glycolysis pathway

  • an electron transport chain

Erklärung

Frage 91 von 107

1

Microorganisms in biofilms:

Wähle eine der folgenden:

  • develop as porous, mushroom-like structures when there are lots of nutrients present in the biofilm

  • typically have the same sensitivity to antibiotics as they do when growing freely in broth culture

  • none of the above

  • - develop as porous, mushroom-like structures when there are lots of nutrients present in the biofilm
    - typically have the same sensitivity to antibiotics as they do when growing freely in broth culture

Erklärung

Frage 92 von 107

1

Transposons _________.

Wähle eine der folgenden:

  • can cause frameshift mutations

  • are small pieces of DNA that can move from one location in a DNA molecule to another location

  • on the same or a different chromosome

  • - can cause frameshift mutations
    - are small pieces of DNA that can move from one location in a DNA molecule to another location

  • none of the above

Erklärung

Frage 93 von 107

1

Transduction is the transfer of genes from one bacterium to another by ________.

Wähle eine der folgenden:

  • naked DNA in solution

  • viruses

  • direct contact between the cells

  • cell fusion

Erklärung

Frage 94 von 107

1

The scanning electron microscope is primarily used to visualize the _______.

Wähle eine der folgenden:

  • structure of atoms

  • internal structures of cells

  • structure of large molecules such as proteins

  • surface of cells and objects

Erklärung

Frage 95 von 107

1

The region of logarithmic growth in a bacterial growth curve _________.

Wähle eine der folgenden:

  • can be used to determine the generation time of a microbe

  • is a region where the number of new cells being formed is equal to the number of cells that are dying

  • - is a region where the number of new cells being formed is equal to the number of cells that are dying
    - can be used to determine the generation time of a microbe

  • none of the above

Erklärung

Frage 96 von 107

1

Non-membranous organelles in eukaryotic cells include all of the following EXCEPT:

Wähle eine der folgenden:

  • ribosomes

  • peroxisomes

  • centrioles

  • proteosomes

Erklärung

Frage 97 von 107

1

The purpose of iodine in the Gram stain is to __________.

Wähle eine der folgenden:

  • stain the cells purple

  • stain cells a light red color

  • enhance staining of gram-positive bacteria with crystal violet

  • enhance the staining of gram-negative bacteria with safranin

Erklärung

Frage 98 von 107

1

The theory of biogenesis was proven by ________.

Wähle eine der folgenden:

  • Alexander Fleming

  • Robert Koch

  • Louis Pasteur

  • John Needham

Erklärung

Frage 99 von 107

1

The genetic material of prokaryotic cells is __________.

Wähle eine der folgenden:

  • attached to the cell's cytoskeleton

  • usually a single circular molecule of DNA

  • enclosed in a porous membrane

  • none of the above

Erklärung

Frage 100 von 107

1

A chemoautotroph uses ______ as a carbon source and ______ as an energy source.

Wähle eine der folgenden:

  • CO2 / light

  • CO2 / chemical compounds

  • organic compounds / light

  • organic compounds / chemical compounds

Erklärung

Frage 101 von 107

1

The structural polymer that protects bacterial cells from osmotic lysis is the _______.

Wähle eine der folgenden:

  • cytoplasmic membrane

  • glycocalyx

  • peptidoglycan

  • capsule

Erklärung

Frage 102 von 107

1

The first person to prove that microbes can cause infectious disease in humans was _______.

Wähle eine der folgenden:

  • Antoni van Leeuwenhock

  • Robert Koch

  • Louis Pasteur

  • Francesco Redi

Erklärung

Frage 103 von 107

1

Snapping division in prokaryotic cells produces _______.

Wähle eine der folgenden:

  • packets of 8 cocci

  • chains of rods

  • spirochetes

  • V and Y shapes

Erklärung

Frage 104 von 107

1

Osmotic pressure is defined as the hydrostatic pressure required to ______.

Wähle eine der folgenden:

  • stop the net flow of water across a semi-permeable membrane

  • prevent a cell from bursting

  • cause a cell to burst

  • none of the above

Erklärung

Frage 105 von 107

1

Nucleosomes are _________.

Wähle eine der folgenden:

  • present in both prokaryotic and eukaryotic cells

  • complexes of DNA and histones

  • extra-chromosomal pieces of DNA

  • - present in both prokaryotic and eukaryotic cells
    - complexes of DNA and histones

Erklärung

Frage 106 von 107

1

Microbes are beneficial because they _______.

Wähle eine der folgenden:

  • recycle vital elements from dead organisms and organic wastes

  • produces oxygen

  • - recycle vital elements from dead organisms and organic wastes
    - produces oxygen

  • none of the above

Erklärung

Frage 107 von 107

1

The conversion of nitrogen gas (N2) into ammonia _______.

Wähle eine der folgenden:

  • requires siderophores

  • is carried out by all plants

  • occurs during photosynthesis in plants

  • none of the above

Erklärung

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