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Microbial Exam 1 Oldies Questions Compilation

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Microbial Exam 1 Oldies Questions Compilation

Questão 1 de 107

1

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

Selecione uma das seguintes:

  • cholesterol

  • phospholipids

  • proteins

  • phospholipids and proteins

  • cholesterol, phospholipids, and proteins

Explicação

Questão 2 de 107

1

An acidophile is an organism that ____.

Selecione uma das seguintes:

  • 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

Explicação

Questão 3 de 107

1

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

Selecione uma das seguintes:

  • obligate aerobes

  • facultative anaerobes

  • microaerophile

  • aerotolerant anaerobes

  • obligate anaerobes

Explicação

Questão 4 de 107

1

Bacteria that lack cell walls readily lyse in _____ solution.

Selecione uma das seguintes:

  • hypotonic

  • hypertonic

  • isotonic

  • hypertonic and hypotonic

  • none of the above

Explicação

Questão 5 de 107

1

Bacteria in the logarithmic phase of growth ______.

Selecione uma das seguintes:

  • 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

Explicação

Questão 6 de 107

1

Capsules are important virulence factors for bacteria because they ____.

Selecione uma das seguintes:

  • 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

Explicação

Questão 7 de 107

1

Chains of cocci are called _______.

Selecione uma das seguintes:

  • streptococci

  • diplococci

  • staphylococci

  • sarcinae

  • coccobacilli

Explicação

Questão 8 de 107

1

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

Selecione uma das seguintes:

  • penicillin

  • hand and instrument washing in chlorinated lime

  • prayer

  • having doctors deliver babies instead of midwives

  • none of the above

Explicação

Questão 9 de 107

1

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

Selecione uma das seguintes:

  • CO2 and H2O

  • citrate

  • ethanol and CO2

  • glycogen

  • two molecules of pyruvate

Explicação

Questão 10 de 107

1

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

Selecione uma das seguintes:

  • reducing

  • differential

  • selective

  • chemically defined

  • enrichment

Explicação

Questão 11 de 107

1

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

Selecione uma das seguintes:

  • thermophiles

  • mesophiles

  • psychrophiles

  • psychrotrophs

  • extreme thermophiles

Explicação

Questão 12 de 107

1

Negative stains _______.

Selecione uma das seguintes:

  • 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

Explicação

Questão 13 de 107

1

Siderophores are _______.

Selecione uma das seguintes:

  • 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

Explicação

Questão 14 de 107

1

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

Selecione uma das seguintes:

  • peptidoglycan

  • teichoic acid

  • lipopolysaccharide

  • phospholipid

  • porins

Explicação

Questão 15 de 107

1

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

Selecione uma das seguintes:

  • 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

Explicação

Questão 16 de 107

1

The outer membrane of gram-negative bacteria contains ________.

Selecione uma das seguintes:

  • peptidoglycan

  • lipopolysaccharide

  • porins

  • - lipopolysaccharide
    - porins

  • - peptidoglycan
    - lipopolysaccharide
    - porins

Explicação

Questão 17 de 107

1

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

Selecione uma das seguintes:

  • 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

Explicação

Questão 18 de 107

1

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

Selecione uma das seguintes:

  • 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

Explicação

Questão 19 de 107

1

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

Selecione uma das seguintes:

  • biochemical tests

  • morphological features

  • DNA hybridization

  • differential staining

  • DNA base composition

Explicação

Questão 20 de 107

1

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

Selecione uma das seguintes:

  • lysozyme

  • superoxide dismutase

  • catalase

  • peroxidase

  • oxygenase

Explicação

Questão 21 de 107

1

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

Selecione uma das seguintes:

  • morphological criteria

  • biochemical tests

  • rRNA nucleotide sequence

  • - morphological criteria
    - biochemical tests

Explicação

Questão 22 de 107

1

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

Selecione uma das seguintes:

  • 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

Explicação

Questão 23 de 107

1

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

Selecione uma das seguintes:

  • conjugation

  • transformation

  • transportation

  • transduction

  • lysogeny

Explicação

Questão 24 de 107

1

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

Selecione uma das seguintes:

  • 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

Explicação

Questão 25 de 107

1

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

Selecione uma das seguintes:

  • sterilization

  • antisepsis

  • disinfection

  • sanitization

  • bacteriostasis

Explicação

Questão 26 de 107

1

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

Selecione uma das seguintes:

  • 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

Explicação

Questão 27 de 107

1

Which of the following statements about endospores is FALSE?

Selecione uma das seguintes:

  • 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

Explicação

Questão 28 de 107

1

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

Selecione uma das seguintes:

  • 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

Explicação

Questão 29 de 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?

Selecione uma das seguintes:

  • 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

Explicação

Questão 30 de 107

1

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

Selecione uma das seguintes:

  • 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

Explicação

Questão 31 de 107

1

Which of the following statements about microbial growth is FALSE?

Selecione uma das seguintes:

  • 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

Explicação

Questão 32 de 107

1

Which of the following statements about porins is true?

Selecione uma das seguintes:

  • 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

Explicação

Questão 33 de 107

1

Which of the following statements about lipopolysaccharides is FALSE?

Selecione uma das seguintes:

  • 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

Explicação

Questão 34 de 107

1

Which of the following statements about peptidoglycan is FALSE?

Selecione uma das seguintes:

  • 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

Explicação

Questão 35 de 107

1

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

Selecione uma das seguintes:

  • conjugation

  • transformation

  • transduction

  • crossing over

Explicação

Questão 36 de 107

1

Transcription is _________.

Selecione uma das seguintes:

  • the process of protein synthesis

  • occurs on ribosomes

  • - the process of protein synthesis
    -occurs on ribosomes

  • none of the above

Explicação

Questão 37 de 107

1

Which of the following are eukaryotes?

Selecione uma das seguintes:

  • Bacteria

  • Archaea

  • Fungi

  • Viruses

  • None of the above

Explicação

Questão 38 de 107

1

Which of the following statements about fermentations is FALSE?

Selecione uma das seguintes:

  • 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

Explicação

Questão 39 de 107

1

Which of the following statements about fimbriae is FALSE?

Selecione uma das seguintes:

  • 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

Explicação

Questão 40 de 107

1

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

Selecione uma das seguintes:

  • 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

Explicação

Questão 41 de 107

1

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

Selecione uma das seguintes:

  • brightfield microscope

  • darkfield microscope

  • phase-contrast microscope

  • fluorescence microscope

  • transmission electron microscope

Explicação

Questão 42 de 107

1

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

Selecione uma das seguintes:

  • 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

Explicação

Questão 43 de 107

1

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

Selecione uma das seguintes:

  • 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

Explicação

Questão 44 de 107

1

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

Selecione uma das seguintes:

  • 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

Explicação

Questão 45 de 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.

Selecione uma das seguintes:

  • 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

Explicação

Questão 46 de 107

1

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

Selecione uma das seguintes:

  • 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

Explicação

Questão 47 de 107

1

The cytoskeleton of prokaryotic cells is _______.

Selecione uma das seguintes:

  • 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

Explicação

Questão 48 de 107

1

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

Selecione uma das seguintes:

  • mycobacteria

  • Bacillus species

  • Streptococci

  • Staphylococci

Explicação

Questão 49 de 107

1

The term aciduric means that a microbe _____.

Selecione uma das seguintes:

  • 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

Explicação

Questão 50 de 107

1

Which of the following statements about prokaryotic flagella is true?

Selecione uma das seguintes:

  • 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

Explicação

Questão 51 de 107

1

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

Selecione uma das seguintes:

  • Francesco Redi

  • Paul Ehrlich

  • Robert Kock

  • Louis Pasteur

  • Joseph Lister

Explicação

Questão 52 de 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?

Selecione uma das seguintes:

  • 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

Explicação

Questão 53 de 107

1

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

Selecione uma das seguintes:

  • phosphoglyceride lipids

  • porins

  • the O-specific polysaccharide chain

  • the lipoprotein

  • lipid A

Explicação

Questão 54 de 107

1

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

Selecione uma das seguintes:

  • transferred to NADH

  • lost as heat

  • left in the lactic acid molecules

  • converted into ATP

Explicação

Questão 55 de 107

1

Viable (standard) plate counts are done by _______.

Selecione uma das seguintes:

  • 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

Explicação

Questão 56 de 107

1

Transmission electron microscopes _______.

Selecione uma das seguintes:

  • 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

Explicação

Questão 57 de 107

1

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

Selecione uma das seguintes:

  • molecular oxygen

  • singlet oxygen

  • peroxide anion

  • superoxide anion

  • hydroxyl free radical

Explicação

Questão 58 de 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 ____.

Selecione uma das seguintes:

  • defined culture medium

  • complex culture medium

  • selective culture medium

  • reducing culture medium

  • candle jar

Explicação

Questão 59 de 107

1

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

Selecione uma das seguintes:

  • 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

Explicação

Questão 60 de 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.

Selecione uma das seguintes:

  • 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

Explicação

Questão 61 de 107

1

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

Selecione uma das seguintes:

  • negative stain

  • endospore stain

  • acid-fast stain

  • gram stain

Explicação

Questão 62 de 107

1

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

Selecione uma das seguintes:

  • 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

Explicação

Questão 63 de 107

1

Which of the following statements is true of the prokaryotes?

Selecione uma das seguintes:

  • 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

Explicação

Questão 64 de 107

1

The conditions for historical pasteurization are _________.

Selecione uma das seguintes:

  • 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

Explicação

Questão 65 de 107

1

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

Selecione uma das seguintes:

  • proteosomes

  • the Golgi apparatus

  • the endoplasmic reticulum

  • mitochondria

  • lysosomes

Explicação

Questão 66 de 107

1

The endoplasmic reticulum of eukaryotic cells _________.

Selecione uma das seguintes:

  • 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

Explicação

Questão 67 de 107

1

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

Selecione uma das seguintes:

  • 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

Explicação

Questão 68 de 107

1

Teichuronic acids are:

Selecione uma das seguintes:

  • 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

Explicação

Questão 69 de 107

1

Streptococci divide ______.

Selecione uma das seguintes:

  • 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

Explicação

Questão 70 de 107

1

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

Selecione uma das seguintes:

  • dephosphorylation

  • substrate level phosphorylation

  • photophosphorylation

  • oxidative phosphorylation

Explicação

Questão 71 de 107

1

Reducing media are used to grow ________.

Selecione uma das seguintes:

  • microaerophilic microbes

  • obligate anaerobes

  • chemoautotrophs

  • capnophilic microbes

Explicação

Questão 72 de 107

1

Protozoa historically ___________.

Selecione uma das seguintes:

  • none of the above

  • are single celled organisms

  • have a prokaryotic cell structure

  • carry out photosynthesis

Explicação

Questão 73 de 107

1

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

Selecione uma das seguintes:

  • Mycobacterium species

  • Clostridium species

  • Bacillus species

  • - Clostridium species
    - Bacillus species

  • - Mycobacterium species
    - Clostridium species
    - Bacillus species

Explicação

Questão 74 de 107

1

Peptidoglycan is __________________.

Selecione uma das seguintes:

  • 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

Explicação

Questão 75 de 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.

Selecione uma das seguintes:

  • 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

Explicação

Questão 76 de 107

1

Passive transport _________.

Selecione uma das seguintes:

  • none of the above

  • occurs only in prokaryotic cells

  • requires ATP

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

Explicação

Questão 77 de 107

1

A fastidious microbe is a microbe that ________.

Selecione uma das seguintes:

  • 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

Explicação

Questão 78 de 107

1

Microbes are ecologically important because they _______.

Selecione uma das seguintes:

  • 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

Explicação

Questão 79 de 107

1

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

Selecione uma das seguintes:

  • axial filaments

  • microfilaments

  • fimbriae

  • microtubules

  • cilia

Explicação

Questão 80 de 107

1

An obligate anaerobe produces adequate or high levels of __________.

Selecione uma das seguintes:

  • none of the above

  • peroxidase

  • catalase

  • superoxide dismutase

Explicação

Questão 81 de 107

1

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

Selecione uma das seguintes:

  • none of the above

  • measuring dry weight

  • measuring turbidity

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

Explicação

Questão 82 de 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.

Selecione uma das seguintes:

  • 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.

Explicação

Questão 83 de 107

1

Eukaryotic flagella _______.

Selecione uma das seguintes:

  • 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

Explicação

Questão 84 de 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 _____.

Selecione uma das seguintes:

  • Na+ ions / Na+ ions

  • K+ ions / Na+ ions

  • K+ ions / K+ ions

  • Na+ ions / K+ ions

Explicação

Questão 85 de 107

1

Bacteriostasis means that _______.

Selecione uma das seguintes:

  • 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

Explicação

Questão 86 de 107

1

Immunofluorescence tests require ___________.

Selecione uma das seguintes:

  • a phase contrast microscope

  • specific antibodies to a microbe

  • none of the above

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

Explicação

Questão 87 de 107

1

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

Selecione uma das seguintes:

  • none of the above

  • hypotonic lysis

  • inhibition of DNA synthesis

  • inhibition of protein synthesis

Explicação

Questão 88 de 107

1

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

Selecione uma das seguintes:

  • 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

Explicação

Questão 89 de 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.

Selecione uma das seguintes:

  • 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

Explicação

Questão 90 de 107

1

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

Selecione uma das seguintes:

  • peroxisomes

  • oxygen

  • the glycolysis pathway

  • an electron transport chain

Explicação

Questão 91 de 107

1

Microorganisms in biofilms:

Selecione uma das seguintes:

  • 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

Explicação

Questão 92 de 107

1

Transposons _________.

Selecione uma das seguintes:

  • 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

Explicação

Questão 93 de 107

1

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

Selecione uma das seguintes:

  • naked DNA in solution

  • viruses

  • direct contact between the cells

  • cell fusion

Explicação

Questão 94 de 107

1

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

Selecione uma das seguintes:

  • structure of atoms

  • internal structures of cells

  • structure of large molecules such as proteins

  • surface of cells and objects

Explicação

Questão 95 de 107

1

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

Selecione uma das seguintes:

  • 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

Explicação

Questão 96 de 107

1

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

Selecione uma das seguintes:

  • ribosomes

  • peroxisomes

  • centrioles

  • proteosomes

Explicação

Questão 97 de 107

1

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

Selecione uma das seguintes:

  • 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

Explicação

Questão 98 de 107

1

The theory of biogenesis was proven by ________.

Selecione uma das seguintes:

  • Alexander Fleming

  • Robert Koch

  • Louis Pasteur

  • John Needham

Explicação

Questão 99 de 107

1

The genetic material of prokaryotic cells is __________.

Selecione uma das seguintes:

  • attached to the cell's cytoskeleton

  • usually a single circular molecule of DNA

  • enclosed in a porous membrane

  • none of the above

Explicação

Questão 100 de 107

1

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

Selecione uma das seguintes:

  • CO2 / light

  • CO2 / chemical compounds

  • organic compounds / light

  • organic compounds / chemical compounds

Explicação

Questão 101 de 107

1

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

Selecione uma das seguintes:

  • cytoplasmic membrane

  • glycocalyx

  • peptidoglycan

  • capsule

Explicação

Questão 102 de 107

1

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

Selecione uma das seguintes:

  • Antoni van Leeuwenhock

  • Robert Koch

  • Louis Pasteur

  • Francesco Redi

Explicação

Questão 103 de 107

1

Snapping division in prokaryotic cells produces _______.

Selecione uma das seguintes:

  • packets of 8 cocci

  • chains of rods

  • spirochetes

  • V and Y shapes

Explicação

Questão 104 de 107

1

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

Selecione uma das seguintes:

  • 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

Explicação

Questão 105 de 107

1

Nucleosomes are _________.

Selecione uma das seguintes:

  • 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

Explicação

Questão 106 de 107

1

Microbes are beneficial because they _______.

Selecione uma das seguintes:

  • 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

Explicação

Questão 107 de 107

1

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

Selecione uma das seguintes:

  • requires siderophores

  • is carried out by all plants

  • occurs during photosynthesis in plants

  • none of the above

Explicação