BMSC 210 PRACTICE FINAL

Question 1

The ability of humans to resist a disease is called

Answer 1

Immunity

Question 2

Pattern recognition receptors (PRRs) are found on which of the following cells?

Answer 2

Macrophages and neutrophils

Question 3

Adaptive immune responses are directed at pathogen molecules called

Answer 3

antigens

Question 4

An example of a pathogen-associated molecular pattern (PAMP) is

Answer 4

lipopolysaccharide (LPS)

Question 5

Adaptive immunity occurs when

Answer 5

the innate immune response fails to eliminate pathogens in the body and virulent infections persist after the initial innate defense response

Question 6

The pathogen-associated molecular pattern (PAMP) recognized by mannose-binding lectin (MBL) isthe sugar mannose, found as a repeating subunit in

Answer 6

bacterial polysaccharides

Question 7

________ are cytotoxins produced by T cells that cause apoptosis

Answer 7

Granzymes

Question 8

T cells recognize antigens with their

Answer 8

T cell receptors

Question 9

________ is a group of sequentially interacting proteins important in innate and adaptive immunity.

Answer 9

complement

Question 10

The part of the antigen recognized by the antibody or TCR is called the

Answer 10

epitope

Question 11

Unactivated dendritic cells act as antigen presenting cells for which of the following T cell subsets?

Answer 11

Treg only

Question 12

Which of the following T cell subsets is a CD8 T cell?
a) Th2 b) Treg c) None of these. d) Th17

Answer 12

None of the above

Question 13

Proteins derived from infecting viruses are taken up and digested in the cytoplasm in a structure called the

Answer 13

proteasome

Question 14

Antigen-presenting cells present antigens to

Answer 14

T lymphocytes

Question 15

T or F: Th2 cells produce a cytokine that promotes growth and activation of other T cells and activates macrophage

Answer 15

False

Question 16

The cells active in both innate and adaptive immunity develop from common pluripotent precursorsin the bone marrow called

Answer 16

stem cells

Question 17

The body’s noninducible, preexisting ability to recognize and destroy a variety of pathogens or theirproducts is called

Answer 17

innate immunity.

Question 18

Antibodies are found in

Answer 18

milk, mucosal secretions, and serum

Question 19

Enhanced phagocytosis of antibody-sensitized cells is known as

Answer 19

opsonization

Question 20

Substances that induce an immune response are known as

Answer 20

Immunogens

Question 21

Th cells express a ________ protein coreceptor.

Answer 21

CD4

Question 22

Intrinsic properties of immunogens include

Answer 22

appropriate physical form, molecular size, and molecular complexity

Question 23

Communication between cells of the immune system is accomplished in many cases through

Answer 23

cytokines

Question 24

The first defense cells that interact with a pathogen in the body are

Answer 24

macrophages

Question 25

T or F: Helicobacter pylori, when present, is the MOST common single organism found in the stomach.

Answer 25

True

Question 26

Which of the following is NOT found in the gastrointestinal tract of a healthy individual?

Answer 26

protists

Question 27

Which of the following is NOT produced by microorganisms in the gut of humans?

Answer 27

Vitamin C

Question 28

Bacteria make up about ____________ the weight of fecal matter

Answer 28

One-third

Question 29

Which of the following will happen after a person takes an antibiotic orally?
A) All of the other answers b) The growth of normal flora will be inhibited c) Opportunistic microorganisms such as antibiotic resistant Staphylococcus aureas may become established d) The growth of pathogens will be inhibited

Answer 29

A) all of the other answers

Question 30

Saliva is a poor growth medium for bacteria due to

Answer 30

the presence of lysozyme

Question 31

The lower respiratory tract does not have any resident microbial flora

Answer 31

because most organisms are too small to make it to the bronchi

because organisms settle out of the air prior to reaching the trachea

Question 32

The variety of microenvironments on the skin allows the skin to have

Answer 32

a large diversity of the microbiome

Question 33

Gut colonizers are an important source of

Answer 33

amino acids
vitamin K
B vitamins

Question 34

The most stable gut species include

Answer 34

Bacteroides

Question 35

Knowing specifics of a person’s microbiome can potentially lead to

Answer 35

targeted treatment for disease
personalized drug therapies
probiotics made that just target specific imbalances

Question 36

___________ is the growth of microorganisms NOT normally present within a host

Answer 36

Infection

Question 37

Following exposure to a pathogen, events leading to disease—in the correct order— are

Answer 37

adherence, invasion, infection, toxicity

Question 38

Adherence factors include ALL of the following EXCEPT

Answer 38

lipopolysaccharide layers

Question 39

Growth of a microorganism after entering a host is called

Answer 39

colonization

Question 40

Which of the following does NOT occur during the development of dental caries?

Answer 40

Oral microflora produce high concentrations of exoenzymes when sucrose is present

Question 41

The ability of a pathogen to enter a cell, spread, and cause disease is termed

Answer 41

invasion

Question 42

A bacterial infection becomes a disease when

Answer 42

there is tissue damage that impairs host function

Question 43

_____________can vary between strains of an organism depending on the ability to adhere, colonize, and invade a host

Answer 43

Virulence

Question 44

___________organisms are valuable in the production of vaccines

Answer 44

Attenuated

Question 45

Organism X has an L D50 of 2 × 102, and organism Y has an L D50 of 3 × 104. Which organism is more virulent

Answer 45

organism X

Question 46

Which of the following environmental and host factors influence the composition of the resident microbiota on the skin?

Answer 46

age. personal hygiene and weather

Question 47

Which of the following is TRUE about research on the human microbiome?

Answer 47

Advanced nucleic acid sequencing techniques were needed before a good understanding of its microbial abundance and diversity could be developed

Question 48

Which of the following is NOT a major question in the Human Microbiome Project?

Answer 48

How can we reduce the number of microbes on the human body?

Question 49

The damaged areas of teeth caused by organic acids produced by dental plaque are called

Answer 49

dental caries

Question 50

Normal microbiota helps to ________ colonization of pathogenic organisms

Answer 50

prevent

Question 51

Which of these microorganisms is most likely to be found in the human stomach?

Answer 51

Helicobacter pylor

Question 52

Which of the following is NOT true of human gut microbes?

Answer 52

Which of the following is NOT true of human gut microbes?

Question 53

Lysozyme is found throughout our bodies to protect us from infection. Some bacteria can evade this defense

Answer 53

by altering their peptidoglycan

Question 54

Because they are Gram negative, E. coli, Salmonella, and Shigella all produce

Answer 54

endotoxins

Question 55

Which of the following toxins is NOT a cytolytic exotoxin?

Answer 55

Shiga toxin

Question 56

Genes for antiphagocytic proteins, exotoxins, and adherence that are clustered together on a bacterial chromosome are called

Answer 56

pathogenicity islands

Question 57

All of the following are enzymes that increase virulence EXCEPT

Answer 57

cellulase

Question 58

Diphtheria toxin is

Answer 58

an AB toxin

Question 59

Pathogens that can secrete ______________ are more virulent because of the organism’s potential to spread in the host

Answer 59

hyaluronidase

Question 60

Exotoxins classified as AB toxins damage cells by

Answer 60

using the B subunit to attach to the target cell while the A subunit enters and inhibits protein synthesis

Question 61

The host-microbiome supraorganism refers to

Answer 61

a body and all of its associated microbes

Question 62

The human oral microbiota consists of

Answer 62

diverse aerobic and anaerobic microorganisms

Question 63

The vagina of an adult female is

Answer 63

weakly acidic

Question 64

T or F: Endotoxins are the secreted products of living cells, whereas exotoxins are cell bound and released in large amounts ONLY when the cells lyse

Answer 64

False

Question 65

Streptokinase works to ___________ fibrin clots while coagulase works to ___________ fibrin clots

Answer 65

dissolve / promote

Question 66

Healthcare-associated infections (HAI s) are also called

Answer 66

nosocomial infections

Question 67

Which of the following has the highest level of containment and is where drug-resistant Mycobacterium tuberculosis must be studied

Answer 67

BSL-4

Question 68

The antimicrobial susceptibility of a bacterium can be determined by

Answer 68

the tube dilution technique

the disk diffusion test

determining the minimum inhibitory concentration

Question 69

Media that can differentiate organisms based on colony appearance are

Answer 69

differential

Question 70

Aseptic technique in obtaining clinical specimens is essential to ensure bacterial presence is due only to

Answer 70

infection

Question 71

T or F: If an individual is infected with a pathogen, the antibody titer to that pathogen will decrease

Answer 71

False

Question 72

Advantages of qPCR tests over traditional end-point PCR tests include

Answer 72

eliminating the need for agarose gel electrophoresis
continuous monitoring
determining the amount of target DNA present in an original sample

Question 73

In the triple sugar iron test the reaction of hydrogen sulphide produced by bacteria with ferrous ironin the medium produces

Answer 73

blackening of the agar

Question 74

Thayer Martin medium is a selective medium used for the clinical isolation of

Answer 74

Neisseria gonorrhoeae

Question 75

Beta hemolysis on blood agar indicates

Answer 75

complete hemolysis

Question 76

In a dipstick nucleic acid assay, dual reporter and capture probes are used. The capture probe

Answer 76

binds to the dipstick

Question 77

During an infection with Salmonella enterica Serovar Typhi (typhoid fever) as the antibody titre increases

Answer 77

bacteria are cleared from the blood

Question 78

T or F: Monoclonal antibodies are directed to a number of different epitopes on a bacterial antigen

Answer 78

False

Question 79

In a passive (indirect) agglutination test

Answer 79

antibodies or antigens are absorbed or chemically coupled to cells or insoluble particles such as latex beads

Question 80

A Western blot usually involves

Answer 80

protein

Question 81

For a disease to become a pandemic, it must

Answer 81

initially start out as an epidemic and have widespread infections

Question 82

The incidence of BOTH fatal and nonfatal diseases in a population is called

Answer 82

morbidity

Question 83

An endemic disease

Answer 83

is constantly present in the populace

Question 84

The prevalence of a disease is

Answer 84

the total number of both new and existing cases

Question 85

A disease that primarily infects an animal but is occasionally transmitted to humans is called a(n)

Answer 85

zoonosis

Question 86

Carriers contribute to the spread of which of the following diseases?

Answer 86

HIV
Typhoid fever
Hepatitis

Question 87

A disease outbreak that has a large number of cases diagnosed in a very short period time is characteristic of

Answer 87

a common source epidemic

Question 88

COVID-19 is primarily transmitted through

Answer 88

aerosol droplet spread

Question 89

The region of the world with the highest burden of disease as measured by DALYs is

Answer 89

sub-Saharan Africa

Question 90

If the reproduction number for COVID-19 is >1, that means that

Answer 90

each existing infection causes more than one new infection possibly leading to an outbreak

Question 91

The basis for blood typing is referred to as

Answer 91

hemagglutination

Question 92

T or F: some infectious agents, such as Neisseria gonorrhoeae, do NOT elicit a systemic immune response

Answer 92

True

Question 93

Laboratories that work with extremely low risk pathogens are classified as

Answer 93

BSL-1

Question 94

Antibody titer can be measured by

Answer 94

agglutination

Question 95

Indirect EIA is used to detect

Answer 95

antibodies

Question 96

Which of the following immunological tests would allow the specific identification of a microorganism directly in infected tissues?

Answer 96

Fluorescent antibody (FA)

Question 97

SYBR Green, commonly used in qPCR, binds nonspecifically to ________, indicating the presence of the PCR product

Answer 97

dsDNA

Question 98

A disease that is present in unusually high numbers throughout the world is called

Answer 98

a pandemic

Question 99

Answer

Answer 99

host-to-host epidemic.

Question 100

The basic reproduction number of a pathogen such as SARS-CoV-2 (causes COVID-19)

Answer 100

can vary during an epidemic based on infection control measures

Question 101

Disease ________ is measured by the total number of new reported disease cases within a population over a period of time

Answer 101

incidence

Question 102

An inanimate object that transmits infectious agents between hosts is most appropriately called a

Answer 102

fomite

Question 103

Which of the following is an example of herd immunity

Answer 103

If 70% of the population is immunized against polio, the disease will be essentially absent from the population

Question 104

Typhoid Mary is an example of a ________, because she was infected by the causative agent ʺ ʺfor typhoid fever yet was asymptomatic

Answer 104

carrier

Question 105

You are an epidemiologist analyzing the onset of a given epidemic and note that the epidemic is indicated by a notable sharp rise in the number of cases reported daily over a brief interval. This indicates that the mode of transmission is

Answer 105

common source

Question 106

T or F: A disease that is constantly present in low numbers is called an acute disease.

Answer 106

False

Question 107

In Ontario and many other provinces, the number of cases of COVID-19 is increasing and authorities are concerned because the reproduction number indicates transmission to multiple people. In this case the R0 number would be

Answer 107

> 1

Question 108

The blotting of proteins from polyacrylamide gels to nitrocellulose paper, and the subsequent identification by specific antibodies, is called a(n) ________ blot

Answer 108

Western

Question 109

MacConkey agar and eosin-methylene blue (EMB) agar are ________ media

Answer 109

both selective and differential

Question 110

An Etest® is a clinical tool used for the determination of

Answer 110

he minimum inhibitory concentration (MIC) value of an antimicrobial agent

Question 111

The most prevalent STI globally is

Answer 111

Chlamydia trachomatis

Question 112

Neisseria gonorrhoeae is a

Answer 112

Gram-negative diplococcus

Question 113

The current treatment for gonorrhea is

Answer 113

Combination therapy with ceftriaxone and azithromycin

Question 114

Gonorrhea can be diagnosed by

Answer 114

Gram stain, esp in men
Biochemical tests
nucleic acid amplification tests

Question 115

If a chancre forms on your body, what disease would you likely have

Answer 115

syphilis

Question 116

What is a typical symptom of secondary syphilis

Answer 116

generalized skin rash

Question 117

Which drugs would you use to treat penicillin-resistant Neisseria gonorrhoeae?

Answer 117

ceftriaxone plus azithromycin

Question 118

Kaposi’s sarcoma causes cancer of the cells lining the blood vessels, which forms purple splotcheson the skin and occurs during co-infection of HIV and

Answer 118

human herpesvirus 8

Question 119

T or F: There are safe and effective HIV-2 vaccines available, but because HIV-1 has such high genetic variability, the vaccines are of little use to prevent AIDS

Answer 119

True

Question 120

HIV-1

Answer 120

targets T-helper cells
argets macrophage
is a retrovirus

Question 121

The CD4 cell surface protein binds to which HIV protein(s)

Answer 121

gp120.gp41

Question 122

Is it possible for humans to have immunity to HIV infections and, if so, how?

Answer 122

Yes, by expressing a non-HIV binding variant of CCR5

Question 123

HPV is a

Answer 123

virus

Question 124

T or F: Upper respiratory pathogens are generally more deadly than lower respiratory pathogens

Answer 124

False

Question 125

Destroyed tissue throughout the lungs and the presence of acid-fast bacteria in a sputum sample likely indicate infection by

Answer 125

Mycobacterium tuberculosis

Question 126

a pseudomembrane is found in cases of

Answer 126

Diphtheria

Question 127

Diphtheria is caused by strains of C. diphtheriae which are ________

Answer 127

lysogenized by bacteriophage B

Question 128

T or F: Mycobacteria are acid-fast

Answer 128

True

Question 129

Neisseria meningitidis belongs to the phylum

Answer 129

Proteobacteria

Question 130

Which of the following diseases is NOT caused by an airborne virus?

Answer 130

scarlet fever

Question 131

Why should pregnant women NOT be immunized with the rubella vaccine?

Answer 131

Rubella virus can infect the fetus by placental transmission and cause serious fetal abnormalities

Question 132

Varicella-zoster virus (VZV) causes which disease

Answer 132

chicken pox

Question 133

Which symptom below does NOT correctly distinguish a cold from influenza (respectively)

Answer 133

malaise: common / rare

Question 134

Reassortment of a virus that results in antigenic shift most commonly occurs in

Answer 134

any animal infected with more than one virus strain

Question 135

The Ebola virus targets cells of the

Answer 135

liver and spleen

Question 136

Although a nonhuman reservoir for Helicobacter pylori has not been identified, it is considered a direct contact disease because

Answer 136

it occurs in clusters and predominates in families

Question 137

Lyme disease can be transmitted by being bitten by an

Answer 137

infected tick

Question 138

A characteristic symptom of Lyme disease is

Answer 138

a bull’s eye rash

Question 139

Plague, also known as the Black death is caused by

Answer 139

a bacterium

Question 140

T or F: the rat flea Zenopsylla cheopsis carries cells of Yersinia pestis

Answer 140

True

Question 141

The reticulate body (RB) of C. trachomatis

Answer 141

is intracellular

Question 142

Lymphogranuloma venereum is a sexually transmitted disease caused by distinct strains of

Answer 142

Chlamydia trachomatis

Question 143

N. gonorrhoeae infections can be diagnosed by

Answer 143

Gram stain esp in male urethral specimens
PCR
biochemical tests

Question 144

The recommended treatment for infections with Neisseria gonorrhoeae is

Answer 144

ceftriaxone plus azithromycin

Question 145

Tertiary syphilis

Answer 145

can be manifested in neurological and cardiovascular complications

Question 146

Which of the following does NOT apply to bacterial pathogens affecting the respiratory tract?

Answer 146

Most respiratory bacterial pathogens do not respond to antibiotic therapy.

Question 147

The causative agent of streptococcal pharyngitis, also known as strep throat, is

Answer 147

Streptococcus pyogenes

Question 148

The pathogenicity of strains of Streptococcus pneumoniae is because they

Answer 148

carry an antiphagocytic capsule

Question 149

T or F: Infections by flesh-eating bacteria can occur when exotoxins A, B, C, and F and the bacterial ʺ ʺsurface M protein of Streptococcus pyogenes act as superantigens

Answer 149

True

Question 150

Which of the following microbial groups is most resistant to desiccation due to their cell wall?

Answer 150

Gram-positive

Question 151

Shingles is caused by latent

Answer 151

varicella-zoster virus

Question 152

The primary disease reservoir for plague is

Answer 152

rats

Question 153

The MMR vaccine comprises

Answer 153

Attenuated live virus

Question 154

In bubonic plague, buboes are swellings formed in the lymph nodes and filled with

Answer 154

plague

Question 155

The disease whose symptoms are most closely related to the symptoms of chronic syphilis is

Answer 155

chronic Lyme disease

Question 156

Thayer Martin medium is used for growing

Answer 156

Neisseria gonorrhoea

Question 157

Once a person has been infected with Neisseria gonorrhoeae, the individual

Answer 157

can be reinfected immediately because of the diversity of strains and frequency of mutation

Question 158

Risks for acquiring a sexually transmitted infection do NOT include

Answer 158

using condoms

Question 159

Which of the following is TRUE of tuberculosis

Answer 159

The causative agent can remain dormant in macrophages

Question 160

Loeffler’s medium inhibits the growth of most organisms and is commonly used to cultivate

Answer 160

Corynebacterium diphtheriae

Question 161

T or F: The immune response may be as important as antibiotics in the elimination of Bordetella pertussisfrom the body

Answer 161

True

Question 162

Minor changes in influenza virus antigens due to gene mutations is known as

Answer 162

antigenic drift

Question 163

Murine toxin is a ________ that is a respiratory inhibitor and lethal to mice.

Answer 163

Yersinia pestis exotoxin

Question 164

A positive tuberculin test means a patient

Answer 164

may have active disease, been previously exposed to Mycobacterium tuberculosis, or may have a current inapparent infection

Question 165

Colds are mostly caused by

Answer 165

rhinoviruses

Question 166

Impetigo is due to an infection caused by

Answer 166

either Staphylococcus aureus or Streptococcus pyogenes

Question 167

T or F: Reassortment of the genes of the influenza virus is facilitated by the fact that the genome is segmented

Answer 167

True

Question 168

Which of the following statements about chlamydial infections is TRUE

Answer 168

Chlamydial diseases can lead to acute complications

Question 169

Influenza A virus can be identified by which of the following surface glycoproteins?

Answer 169

Both HA and NA

Question 170

Which method would be the MOST powerful approach to isolating a single mutant from a population of billions?
a) replica plating
b) assay for the loss of function
c) selection for a gain of function
d) screen for the mutant

Answer 170

selection for a gain of function

Question 171

Which of the following can restore a frameshift mutation?a) another frameshift, microdeletion, and microinsertion
b) microinsertion
c) microdeletion
d) another frameshift

Answer 171

another frameshift, microdeletion, and microinsertion

Question 172

Consider a mutation in which the change is from UAC to UAU. Both codons specify the amino acid tyrosine. Which type of point mutation is this?
a) Silent mutation
b) Missense mutation
c) Nonsense mutation
d) Frameshift mutation

Answer 172

Silent mutation

Question 173

Nutritionally defective mutants can be detected by the technique of
a) transversion.
b) replica plating.
c) transposon mutagenesis.
d) selection

Answer 173

b) replica plating.

Question 174

A mutation in a particular gene that results in the premature halting of transcription (and, consequently, protein translation) is a___________ mutation.
a) transition
b) complementary
c) nonsense
d) missense

Answer 174

c) nonsense

Question 175

A mutant that has a nutritional requirement for growth is an example of a(n)
a) auxotroph
.b) organotroph.
c) heterotroph.
d) autotroph

Answer 175

a) auxotroph

Question 176

Second-site mutations that compensate for the effects of another mutation are known as
a) transversions.
b) transitions.
c) frameshift mutations.
d) suppressor mutations

Answer 176

d) suppressor mutations

Question 177

You work for a biotechnology company that uses Streptomyces strains to produce pharmaceutical products. A phage has infected and killed some of your Streptomyces strains during production, resulting in dramatically decreased yields. To protect the strains from infection you propose to
a) transform the Streptomyces strains with plasmids encoding antibody proteins that will protect them from phage infection.
b) infect the Streptomyces strains with a helper phage that will help the strains resist infection.
c) introduce gene transfer agents into the Streptomyces cultures to transfer antibiotic resistance genes into your Streptomyces strains.
d) design and insert CRISPR spacer sequences into the genomes of your strains that are complementary to the genomes of the phages that are infecting the cultures

Answer 177

d) design and insert CRISPR spacer sequences into the genomes of your strains that are complementary to the genomes of the phages that are infecting the culture

Question 178

The conversion of non-toxin-producing strains of Corynebacterium diphtheriae to toxin-producing (pathogenic) strains following lysogeny with phage is an example of
a) phage conversion.
b) transduction.
c) transposition.
d) lysogeny switching

Answer 178

a) phage conversion.

Question 179

F+ strains of Escherichia coli
a) transfer the F factor to recipient cells at a high frequency.
b) do not have an F factor.
c) have the F factor as a plasmid.
d) have an integrated F factor.

Answer 179

c) have the F factor as a plasmid

Question 180

The uptake of free DNA from the environment is referred to as ________, while the transfer of DNA with cell-to-cell contact is known as ________

Answer 180

a) transformation / conjugation

Question 181

When DNA is transferred into a prokaryotic cell, it may
a) replicate independent of the host chromosome
.b) recombine with the host chromosome.
c) be degraded by enzymes.
d) be degraded by enzymes, replicate independent of the host chromosome, or recombine with the host chromosome

Answer 181

d) be degraded by enzymes, replicate independent of the host chromosome, or recombine with the host chromosome

Question 182

A plasmid may
a) replicate independently of the chromosome, integrate into the chromosome, or be transferred cell-to-cell during conjugation.
b) replicate independently of the chromosome.
c) be transferred cell-to-cell during conjugation.
d) be integrated into the chromosome

Answer 182

a) replicate independently of the chromosome, integrate into the chromosome, or be transferred cell-to-cell during conjugation.

Question 183

Consider the following experiment. First, large populations of two mutant strains of Escherichia coli are mixed, each requiring a different, single amino acid. After plating them onto a minimal medium, 45 colonies grew. Which of the following may explain this result?
A) The colonies may be due to back mutation (reversion).
B) The colonies may be due to recombination.

a) B only
b) A only
c) Either A or B is possible
d) Neither A nor B is possible

Answer 183

c) Either A or B is possible

Question 184

The F (fertility) plasmid contains a set of genes that encode for the ________ proteins that are essential in conjugative transfer of DNA.
a) SOS repair
b) pili
c) transduction
d) transformation

Answer 184

b) pili

Question 185

A point mutation refers to mutations involvingʺ ʺ
a) the gain of a base pair (microinsertion).
b) a substitution, deletion, or addition of one base-pair.
c) the deletion of a base pair (microdeletion).
d) a base-pair substitution

Answer 185

a substitution, deletion, or addition of one base-pair

Question 186

Microinsertions and microdeletions often result in ________ mutations.
a) frameshift
b) auxotrophic
c) advantageous
d) silent

Answer 186

frameshift

Question 187

Which of the following methods may introduce foreign DNA into a recipient?
a) Conjugation
b) Transformation, transduction, and conjugation
c) Transformation
d) Transduction

Answer 187

b) Transformation, transduction, and conjugation

Question 188

The CRISPR system
a) repairs DNA and increases DNA damage tolerance during times of stress.
b) facilitates homologous recombination through a complex system of proteins and clustered repeats.
c) recognizes foreign DNA sequences that have previously entered the cell and directs the Cas proteins to destroy them.
d) synthesizes gene transfer agents during stationary phase.

Answer 188

recognizes foreign DNA sequences that have previously entered the cell and directs the Cas proteins to destroy them.

Question 189

Lysogeny probably carries a strong selective advantage for the host cell because it
a) confers resistance to infection by viruses of the same type.
b) confers resistance to infection by many virus types and prevent cell lysis.
c) confers resistance to infection by viruses of a different type (or strain).
d) prevents cell lysis

Answer 189

confers resistance to infection by viruses of the same type

Question 190

Which is NOT true about PCR?a) It uses oligonucleotide primers that are complementary to the flanking regions of target DNA
b) It amplifies DNA sequences
c) It is used for making DNA for cloning and DNA sequencing
d) It uses DNA polymerases from psychrophilic microbes

Answer 190

d) It uses DNA polymerases from psychrophilic microbes

Question 191

If you wanted to compare the relative abundance of mRNA transcribed for a specific gene by two different strains of bacteria, you would perform a) a Northern blot
b) a Southern blot
c) site directed mutagenesis
d) a blot identifying proteins

Answer 191

Northern blot

Question 192

27) Nucleic acid probes comprise
a) proteins which bind to DNA at specific regions
b) ss DNA fragments complementary to the sequence of interest
c) None of the other answers
d) DS DNA fragments complementary to the sequence of interes

Answer 192

b) ss DNA fragments complementary to the sequence of interest

Question 193

Cutting DNA with EcoR1 will produce
a) 3’ overhangs
b) a mixture of blunt ends and 5’overhangs
c) blunt ends
d) 5’ overhangs

Answer 193

5’ overhands

Question 194

Genetic engineering requires
a) a cloning vector and a host for expression
b) a vector and a host for gene expression
c) various genetic building blocks and a host for expression
d) various genetic building blocks, a cloning vector and a host for expression

Answer 194

various genetic building blocks, a cloning vector and a host for expression

Question 195

During gene cloning, the vector and the foreign DNA are cleaved ________ restriction enzyme(s) and then are joined ________.
a) the same/ DNA polymerase
b) the same / DNA ligase
c) different/ DNA ligase
d) different/ DNA polymerase

Answer 195

b) the same / DNA ligase

Question 196

What is NOT true regarding the use of yeast artificial chromosomes (YACs) for cloning?
a) They are circular vectors
b) They contain a gene for selection
c) Large fragments of DNA can be inserted into them
d) They have features to allow them to replicate and segregate like normal eukaryotic chromosomes

Answer 196

They are circular vectors

Question 197

When using a reporter gene to investigate expression of a target protein, the promoter of _________ is ligated to the coding sequence of the ____________.
a) green fluorescent protein / lacZ
b) reporter gene / target gene
c) target gene / reporter gene
d) lacZ / green fluorescent protein

Answer 197

c) target gene / reporter gene

Question 198

The synthetic molecule used in CRISPR gene editing is
a) Cys4
b) Cas9
c) synthetic guide RNA (sgRNA).
d) protospacer adjacent motif (PAM)

Answer 198

synthetic guide RNA (sgRNA)

Question 199

Escherichia coli is naturally transformable
a) True
b) False

Answer 199

False

Question 200

What is referred to as “microbial dark matter?”
a) Comprehensive models for predicting the behavior or properties of an organism
b) Contaminants found in samples prepared for genomic sequencing
c) Prokaryotic organisms that are detected in environmental16S rRNA gene surveys but for which no laboratory cultures are available
d) Microbes that evade the immune system

Answer 200

c) Prokaryotic organisms that are detected in environmental16S rRNA gene surveys but for which no laboratory cultures are available

Question 201

Which type of analysis is typically used for proteomics?a) Mass spectrometry
b) RNA-Seq
c) MDA -multiple displacements amplification
d) Microarrays

Answer 201

a) Mass spectrometry

Question 202

MDA, used in single cell genomics, requires
a) NIMS technology
b) a unique protease
c) a DNA gene chip
d) special viral polymerase with high fidelity

Answer 202

d) special viral polymerase with high fidelity

Question 203

To study an organism’s transcriptome by microarray, _____________ is hybridized onto DNA silica chips containing gene sequences that are ___________ to the sequence.
a) mRNA / identical
b) cDNA / identical
c) mRNA / complementary
d) cDNA / complementary

Answer 203

cDNA / complementary

Question 204

Which is NOT a use for metagenomics?
a) studying possible connections between specific microbial populations in humans and specific diseases
b) assembling complete genomes from isolated community DNA
c) measuring gene expression in populations in order to elucidate function of a gene
d) analyzing environments for the presence and distribution of specific microbial groups

Answer 204

c) measuring gene expression in populations in order to elucidate function of a gene

Question 205

Which is NOT true about the metabolome and metabolomics?
a) The metabolome is the complete set of an organism’s metabolic intermediates.
b) metabolomics was used to reveal the total protein complement of a particular microorganism
c) Metabolomics has been used to characterize the human skin microbiome.
d) The metabolome shows the enzymatic pathways of an organism.

Answer 205

b) metabolomics was used to reveal the total protein complement of a particular microorganism

Question 206

Which of the following organisms is not part of the human mycobiome?
a) Clostridium
b) Saccharomyces
c) Candida
d) Cladosporium

Answer 206

a) Clostridium

Question 207

Computers are used to assemble genomes by deducing the order of DNA fragments based on
a) overlaps
b) mass spectroscopy
c) sequence
d) well position

Answer 207

a) overlaps

Question 208

True or False: To date, humans have been identified as having the largest genome size
a) True
b) False

Answer 208

False

Question 209

Which type of analysis is typically used for proteomics?a) RNA-Seq
b) mass spectrometry
c) microarrays
d) PCR

Answer 209

b) mass spectrometry

Question 210

To study an organism’s transcriptome by microarray, ______________ is hybridized onto DNA silica chips containing gene sequences that are _____to the sequence.
a) mRNA / complementary
b) mRNA / identical
c) cDNA / identical
d) cDNA / complementary

Answer 210

d) cDNA / complementary

Question 211

Why can bacteria undergo rapid evolutionary change?
a) Bacteria pass through numerous bottlenecks
b) Bacteria experience intense selective pressure
c) Bacterial populations are large and can reproduce quickly
d) Bacteria mutate at high rates

Answer 211

c) Bacterial populations are large and can reproduce quickly

Question 212

Which bacterial trait is NOT useful for experiments in evolution?
a) Selective pressure on bacteria is easily manipulated
b) Some bacteria are naturally transformable
c) Bacterial populations are large and reproduce quickly
d) The ancestral organism can be frozen and compared to the evolved descendant

Answer 212

b) Some bacteria are naturally transformable

Question 213

_____________ occur(s) at greater frequency than ______________ in microbial genomes.
a) Deletions / insertions
b) Recombination / mutations
c) Insertions / deletions
d) Mutations / repairs

Answer 213

a) Deletions / insertions

Question 214

The E. coli long-term evolution (LTEE) experiment tracked E. coli for more than _______________ generations.
a) 1,000,000
b) 10,000
c) 1,000
d) 50,000

Answer 214

d) 50,000

Question 215

Two tubes are inoculated from the same tube containing a bacterial culture. The cultures are then transferred every day for two months. All of the media and growth conditions are the same in every tube. After two months of cultivation, the fitness and genotype frequencies of the populations in the two tubes are compared. The fitness of the two cultures is the same, but the genotype frequencies are very different in the two cultures. How is this possible?a) Genetic drift within the small populations in the test tubes resulted in different genotype frequencies
b) Natural selection caused the evolution of different genotype frequencies within the separate test tubes.
c) This result is not possible because different genotype frequencies would result in different fitness levels under the same growth conditions
d) Two months is not long enough for different fitness levels to evolve even if the genotype frequencies change

Answer 215

Genetic drift within the small populations in the test tubes resulted in different genotype frequencies

Question 216

Both deletions and insertions occur during the evolution of microbial genomes. Insertions bring in new genes that may be useful for the cell. Deletions
a) always result in a severe loss of fitness but keep microbial genomes compact
b) may increase fitness of a microorganism by eliminating unneeded genes
c) are uncommon because they are usually lethal
d) always result in a severe loss of fitness for the microorganism

Answer 216

b) may increase fitness of a microorganism by eliminating unneeded genes

Question 217

Chromosomal islands contain clusters of genes for
a) antibiotic resistance
b) DNA repair and replication
c) virulence, biodegradation of pollutants, and symbiotic relationships
d) catabolic and anabolic reactions

Answer 217

c) virulence, biodegradation of pollutants, and symbiotic relationships

Question 218

It is generally accepted that independent mutation, rather than gene duplication, is the mechanism for evolution of most new genes
a) True
b) False

Answer 218

False

Question 219

Which of the following is/are NOT produced using lactic acid bacteria?
a) antibiotics
b) buttermilk
c) silage
d) plasma extender

Answer 219

a) antibiotics

Question 220

Proteobacteria are ALL Gram positive
a) True
b) False

Answer 220

False

Question 221

Select the proper order
a)Domain/Phylum/Class/Order/Family/Genus/Species
b)Species/Genus/Family/Order/Class/Phylum/Domain
c)Domain/Phylum/Family/Class/Order/Genus/Species
d)Phylum/Domain/Order/Class/Family/Genus/Species

Answer 221

a)Domain/Phylum/Class/Order/Family/Genus/Species

Question 222

Rickettsia are
a) Tenericutes
b) Firmicutes
c) Gammaproteobacteria
d) Alphproteobacteria

Answer 222

d) Alphproteobacteria

Question 223

Genera which are characterized by 2,3-butanediol fermentation include
a) Pseudomonas, Vibro
b) Mycoplasma
c) Escherichia, Salmonella
d) Enterobacter, Klebsiella, Serratia

Answer 223

d) Enterobacter, Klebsiella, Serratia

Question 224

Aerobic respiration and anaerobic respiration use different ________________, while chemolithotrophs and chemoorganotrophs use different _________________.
a) electron acceptors / electron donors
b) electron donors / electron acceptors
c) types of phosphorylation / carbon sources
d) proton motive force / photophosphorylation

Answer 224

a) electron acceptors / electron donors

Question 225

The foul-smelling putrescine byproduct suggests activity of
a) amino acid fermentation by clostridia.
b) secondary fermentation.
c) sulfur-oxidizing bacteria.
d) syntrophic carbohydrate metabolism

Answer 225

a) amino acid fermentation by clostridia

Question 226

Most mesophilic organisms can grow in a temperature range of
a) 50-65°C.
b) 20-45°C.
c) 10-20°C.
d) 0-15°C

Answer 226

b) 20-45°C

Question 227

A halotolerant facultative anaerobe would grow BEST in which of the following environments?
a) Oxygenated non-saline
b) Oxygenated saline
c) Oxygen depleted saline
d) Oxygen depleted non-saline

Answer 227

a) Oxygenated non-saline

Question 228

Selective medium differs from differential medium because
a) selective medium permits growth of a particular microbial type while differential medium is used to distinguish between types of organisms.
b) differential medium differentiates pathogens from nonpathogens while selective medium grows only pathogens.
c) differential medium contains growth inhibitors while selective medium does not.
d) selective medium permits growth of more organisms than differential medium

Answer 228

selective medium permits growth of a particular microbial type while differential medium is used to distinguish between types of organisms.

Question 229

Organisms able to live in environments with high sugar concentrations are
a) anaerobic fermenting bacteria.
b) xerophiles.
c) halotolerant.
d) osmophiles

Answer 229

d) osmophiles

Question 230

What temperature is most commonly used in autoclaves to sterilize growth media and other devices prior to experimentation?
a) 101°C
b) 121°C
c) 95°C
d) 140°C

Answer 230

b) 121°C

Question 231

Which term is most relevant in describing the efficacy of an antimicrobial for use in a clinical setting?
a) Sterilization coefficient
b) Lethal dosage
c) Effective dose
d) Minimum inhibitory concentration (MIC)

Answer 231

d) Minimum inhibitory concentration (MIC)

Question 232

Which method would be LEAST effective at sterilizing a glass hockey stick to use in the spread-plate method?
a) Ethanol soaking
b) Gamma radiation
c) Hight temperature short time pasteurization
d) Autoclaving

Answer 232

c) High temperature short time pasteurization

Question 233

Alternative autotrophic routes to the Calvin cycle, such as the reverse citric acid cycle and the hydroxypropionate pathway, are unified in their requirement for
a) NAD(P)H.
b) CO2.
c) organic compound(s) formed.
d) coenzyme A

Answer 233

b) CO2.

Question 234

Identifying carboxysomes in a bacterium suggests it
a) will use the Calvin cycle to convert the concentrated CO2 into biomass.
b) has a deficient Calvin cycle and accumulated CO2.
c) is in a carboxylic acid rich environment and is storing excess quantities for potentially harsh conditions.
d) contains the reverse citric acid cycle

Answer 234

a) will use the Calvin cycle to convert the concentrated CO2 into biomass.

Question 235

Whether an organism is classified as a photoheterotroph or a photoautotroph depends on its
a) carbon source.
b) energy source.
c) oxygen requirements.
d) carbon and energy sources

Answer 235

a) carbon source

Question 236

Which of the following statements is FALSE?
a) Bacteria typically divide by binary fission, producing two daughter cells.
b) In the lag phase, cell death exceeds cell division.
c) In the death phase, bacterial growth may cease as a result of oxygen and nutrient depletion.
d) The generation time of bacteria may vary from species to species

Answer 236

b) In the lag phase, cell death exceeds cell division.

Question 237

The time between inoculation and the beginning of growth is usually called the
a) dormant phase.
b) log phase.
c) decline phase.
d) lag phase

Answer 237

d) lag phase

Question 238

Well-designed microbial activity measurements can reveal ________ of major metabolic reactions in a habitat
a) types
b) both types and rates
c) rates
d) either types or rates (but not both)

Answer 238

b) both types and rates

Question 239

Winogradsky columns are used primarily for enrichment of
a) aerobes, anaerobes, and phototrophs.
b) phototrophs, although occasionally heterotrophs do appear.
c) aerobic cultures, although occasionally anaerobes do appear
d) anaerobic cultures, although occasionally aerobes do appear

Answer 239

a) aerobes, anaerobes, and phototrophs

Question 240

Turbidity measurements are commonly utilized for monitoring
a) conies.
b) planktonic cultures.
c) sessile cultures.
d) biofilms

Answer 240

b) planktonic cultures.

Question 241

Which is one major difference between anaerobic and aerobic respiration?
a) Use of electron transport
b) Electron acceptor
c) Use of proton motive force
d) Electron donor

Answer 241

b) Electron acceptor

Question 242

The use of chemical agents directly on exposed body surfaces to destroy or inhibit vegetative pathogens is
a) sanitization.
b) antisepsis.
c) disinfection.
d) sterilization

Answer 242

b) antisepsis

Question 243

During fermentation, ______________ compounds both donate and accept electrons, with no need for external electron acceptors, but during respiration, ____________ electron donors are oxidized with exogenous compounds serving as electron acceptors.
a) organic / inorganic
b) inorganic / organic
c) organic / inorganic or organic
d) inorganic or organic / organic

Answer 243

organic / inorganic or organic