Micro Exam 3

Front 1

Why is baker's yeast useful for expressing genetically engineered genes?

Back 1

Yeast cells are eukaryotic and so would likely be successful in expressing eukaryotic genes.

Front 2

If you used a broken thermocycler that could not heat above 75°C, which of the following problems could you expect?

Back 2

You would not get any amplification of DNA.

Front 3

Which of the following provides the specificity of the PCR reaction?

Back 3

primers

Front 4

A new arrow labeled "lengthens" could be added between __________.

Back 4

"Taq polymerase" → "primers"

Front 5

Which of the following applications of recombinant DNA technology is NOT controversial?

Back 5

metagenomics

Front 6

Foreign DNA can be inserted into cells using a variety of different methods. Which method involves the formation of microscopic pores in the cell's membrane?

Back 6

electroporation

Front 7

What is the temperature used for the extension step?

Back 7

72 °C

Front 8

How do the strands separate during PCR?

Back 8

The high heat of the denaturation step breaks the hydrogen bonds between the two strands.

Front 9

What is a thermocycler?

Back 9

The machine that controls the heat of the reaction, cycling between the different temperatures of the different steps during PCR

Front 10

What is the sequence of the temperatures of a typical PCR reaction?

Back 10

94 °C, 60 °C, 72 °C

Front 11

Which of the following pairings of recombinant DNA techniques and applications does NOT match?

Back 11

gene silencing: production of subunit vaccines

Front 12

Which statement best describes restriction enzymes?

Back 12

They are important for cloning applications because they can be used to cut DNA at specific nucleotide sequences.

Front 13

Which of the following is NOT a property of useful vectors?

Back 13

They always contain only one gene.

Front 14

Which of the following statements about recombinant DNA technology is FALSE?

Back 14

It has limited application because genes of interest cannot be moved from one type of cell to another.

Front 15

Which of the following methods could be used to identify the source of an outbreak?

Back 15

DNA fingerprinting

Front 16

What is the end goal of PCR?

Back 16

To quickly increase the number of copies of a specific DNA sequence

Front 17

PCR stands for

Back 17

polymerase chain reaction.

Front 18

Which of the following is an application that uses PCR?

Back 18

disease, and providing enough DNA for cloning into another organism

Front 19

Scientists like to use fluorescent proteins for various types of recombinant DNA procedures. You have a very small amount of the gene for a fluorescent protein. You'd like to make a fluorescent bacterium (!). Which of the following represents the correct sequence of procedures that you would use?

Back 19

1. Amplify the gene using PCR.
2. Insert the gene into a plasmid vector.
3. Transform the vector into the bacteria.

Front 20

How do restriction enzymes cut DNA sequences?

Back 20

They cut DNA at sites, called recognition sites, that have specific nucleotide sequences.

Front 21

In general, how might recombinant DNA technology be used to prevent a genetic disorder caused by a mutation in a single gene?

Back 21

To insert a desirable gene, remove an undesirable gene, or replace a defective gene with a functioning gene

Front 22

Which of the following attaches the target gene to a desired location?

Back 22

DNA ligase

Front 23

Why would a recombinant DNA molecule be inserted into a host cell?

Back 23

It can be copied, transcribed, and translated into a desired protein.

Front 24

What is the function of the primers in PCR?

Back 24

They provide a 3’ end for the DNA polymerase.

Front 25

In which direction does DNA polymerase synthesize the new DNA strand?

Back 25

5’ to 3’

Front 26

What provides the energy for DNA polymerization in a PCR reaction?

Back 26

Deoxyribonucleoside triphosphates

Front 27

Why is DNA polymerase from Thermus aquaticusideal for PCR?

Back 27

It can withstand the high temperatures associated with PCR.

Front 28

Which statement regarding agricultural biotechnology is FALSE?

Back 28

Agricultural biotechnology is extremely limited because foreign genes cannot be inserted into plant cells.

Front 29

Which statement best describes restriction enzymes?

Back 29

They are important for cloning applications because they can be used to cut DNA at specific nucleotide sequences.

Front 30

Foreign DNA can be inserted into cells using a variety of different methods. Which method involves the formation of microscopic pores in the cell's membrane?

Back 30

electroporation

Front 31

Which of the following statements about recombinant DNA technology is FALSE?

Back 31

It has limited application because genes of interest cannot be moved from one type of cell to another.

Front 32

You have a small gene that you wish replicated by PCR. After 3 replication cycles, how many double-stranded DNA molecules do you have?

Back 32

8

Front 33

Which of the following is an advantage of using E. coli to make a human gene product?

Back 33

Its genes are well known.

Front 34

Which of the following is NOT a property of useful vectors?

Back 34

They always contain only one gene.

Front 35

Which of the following pairings of recombinant DNA techniques and applications does NOT match?

Back 35

gene silencing: production of subunit vaccines

Front 36

Scientists like to use fluorescent proteins for various types of recombinant DNA procedures. You have a very small amount of the gene for a fluorescent protein. You'd like to make a fluorescent bacterium (!). Which of the following represents the correct sequence of procedures that you would use?

Back 36

1. Amplify the gene using PCR.
2. Insert the gene into a plasmid vector.
3. Transform the vector into the bacteria.

Front 37

Biotechnology involves the

Back 37

use of microorganisms to make desired products, the use of animal cells to make vaccines, and the development of disease-resistanct crop plants.

Front 38

One of the first commercial successes of recombinant DNA technology was the production of human insulin using genetically engineered E. coli.

Back 38

True

Front 39

Bioinformatics is the use of computer technology to compare and analyze genome sequence.

Back 39

True

Front 40

How many pieces will EcoRI produce from the plasmid shown in the figure?

Back 40

2

Front 41

The reaction catalyzed by reverse transcriptase is

Back 41

mRNA → cDNA.

Front 42

A population of cells carrying a desired plasmid is called a

Back 42

clone.

Front 43

You want to determine whether a person has a certain mutant gene. The process involves using a primer and a heat-stable DNA polymerase. This process is

Back 43

PCR.

Front 44

The use of an antibiotic-resistance gene on a plasmid used in genetic engineering makes

Back 44

direct selection possible.

Front 45

PCR can be used to identify an unknown bacterium because

Back 45

the RNA primer is specific.

Front 46

The use of suicide genes in genetically modified organisms is designed to

Back 46

prevent the growth of the modified organisms in the environment.

Front 47

Epidemiology is defined as the study of

Back 47

where and when a disease occurs, and how it is transmitted.

Front 48

What is the role of epidemiology?

Back 48

To learn how to treat and prevent various diseases.

Front 49

Malaria is an infectious disease caused by infection with a protozoan. In certain tropical regions, malaria is constantly present. We would say that malaria is a(n) _________ disease in these regions.

Back 49

endemic

Front 50

Which of the following would be an example of disease transmission via INDIRECT contact?

Back 50

A student sneezes on her test booklet. The instructor grades it and catches her cold.

Front 51

Which of the following is classified as a latent disease?

Back 51

shingles

Front 52

Which of the following statements about the development of infectious diseases is correct?

Back 52

The period of convalescence is the time during which the person regains health and fully recovers (back to the pre-disease state).

Front 53

According to the animation, surgical infections account for what percentage of nosocomial infections?

Back 53

20%

Front 54

What type of nosocomial infection is likely to arise from intravenous catheterizations?

Back 54

Bacteremia

Front 55

How might a patient who is not being treated with an antibiotic still be exposed to an antibiotic?

Back 55

Antibiotics can be used in aerosols, thereby entering the environment.

Front 56

Why are invasive procedures likely to increase the risk of nosocomial infections?

Back 56

These procedures allow microbes from the skin to enter the bloodstream of the patient.

Front 57

How can health care workers reduce the occurrence of nosocomial infections?

Back 57

Practice more stringent aseptic techniques

Front 58

Which of the following statements concerning pathology, infection, and disease is true?

Back 58

Pathology refers to the study of structural and functional changes that occur in the body as a result of a disease.

Front 59

Expected prevalence of a disease is

Back 59

the expected occurrence of a disease based on past observations.

Front 60

In the sixth segment of the animation, why is the disease epidemic in North America?

Back 60

The disease occurs at a higher rate than what would normally be expected in this region

Front 61

In the last segment of the animation, how many regions of the world experience the pandemic during April of year four?

Back 61

Five

Front 62

In the last segment of the animation, when does the first epidemic occur?

Back 62

January of year three

Front 63

If a disease occurs at a fairly stable rate, it is said to be

Back 63

endemic.

Front 64

The following choices list several types of diseases, along with factors that may contribute to their emergence. Which disease and associated factor do NOT match?

Back 64

emergence of avian influenza A (H5N1): use of antibiotics

Front 65

As a health care worker, I am keenly aware of how important it is to avoid harming my patients. I worry about inadvertently transmitting an infectious disease to an already compromised individual. According to the CDC, what is the MOST important thing I can do to avoid this?

Back 65

Wash my hands before interacting with any patient.

Front 66

A patient acquires an infection by touching a contaminated door handle. Which mode of transmission best describes this scenario?

Back 66

indirect contact transmission

Front 67

A dog develops a diarrheal disease after drinking water from a creek during a hike with his owner. Which of the following best describes this method of disease transmission?

Back 67

vehicle transmission

Front 68

Plague is transmitted through the bite of an infected flea. Which of the following best describes this mode of transmission?

Back 68

vector transmission

Front 69

Which of the following is an example of the symbiotic relationship known as mutualism?

Back 69

E. coli within the large intestine

Front 70

The health of the patient

Back 70

should be the primary concern of the healthcare worker.

Front 71

How can surgeons help to limit nosocomial infections?

Back 71

They should perform surgeries and invasive procedures only when absolutely necessary.

Front 72

If a patient notices a healthcare worker not following suggested precautions,

Back 72

they should immediately bring it to the attention of the healthcare worker.

Front 73

Which of the following characteristics of a catheter should be considered, to help minimize the spread of nosocomial infections?

Back 73

Single-use

Front 74

Which of the following statements is true regarding hand washing?

Back 74

Frequent and proper hand washing should be routinely done by patients and by healthcare workers, both prior to and after interaction.

Front 75

Which of the following is a fungal zoonosis that can be transmitted by direct contact?

Back 75

ringworm

Front 76

Koch's postulates established criteria for proving that a specific organism causes a specific disease. Which of the following is NOT one of the criteria given by Koch's postulates?

Back 76

The pathogen must be isolated from inoculated animals and must be different from the original organism.

Front 77

Which of the following would be considered a fomite?

Back 77

An infected toy

Front 78

Which of the following would be considered a vector?

Back 78

A fly carrying disease from fecal matter to food

Front 79

When aerosols containing pathogens spread disease from a distance of less than one meter, it is considered

Back 79

contact transmission.

Front 80

Which of the following is considered a major category of transmission of disease?

Back 80

Contact, vehicle, and vector transmission

Front 81

Which is an example of vehicle disease transmission?

Back 81

The presence of Listeria on undercooked chicken served for dinner

Front 82

One effect of washing regularly with antibacterial agents is the removal of normal microbiota. This can result in

Back 82

increased susceptibility to disease.

Front 83

During a six-month period, 239 cases of pneumonia occurred in a town of 300 people. A clinical case was defined as fever 39°C lasting >2 days with three or more symptoms (i.e., chills, sweats, severe headache, cough, aching muscles/joints, fatigue, or feeling ill). A laboratory-confirmed case was defined as a positive result for antibodies against Coxiella burnetii. Before the outbreak, 2000 sheep were kept northwest of the town. Of the 20 sheep tested from the flock, 15 were positive for C. burnetii antibodies. Wind blew from the northwest, and rainfall was 0.5 cm compared with 7 to 10 cm during each of the previous three years.

Back 83

Coxiella burnetii.

Front 84

The yeast Candida albicans does not normally cause disease because of ______.

Back 84

the normal microbiota

Front 85

A commensal bacterium

Back 85

may also be an opportunistic pathogen.

Front 86

The major significance of Robert Koch's work is that

Back 86

microorganisms cause disease.

Front 87

A disease in which the causative agent remains inactive for a time before producing symptoms is referred to as

Back 87

latent.

Front 88

Symptoms of disease differ from signs of disease in that symptoms

Back 88

are changes felt by the patient.

Front 89

The graph in the figure shows the incidence of polio in the United States. The period between 1945 and 1955 indicates a(n)

Back 89

epidemic level.

Front 90

Which of the following is NOT a predisposing factor of disease?

Back 90

None of the answers are correct; all of these are predisposing factors of disease.

Front 91

In which of the following patterns of disease does the patient experience no signs or symptoms?

Back 91

incubation and convalescence

Front 92

Which of the following is a fomite?

Back 92

a hypodermic needle

Front 93

Which one of the following is NOT a zoonosis?

Back 93

None of the answers is correct; all of these are zoonoses.

Front 94

Biological transmission differs from mechanical transmission in that biological transmission

Back 94

involves specific diseases.

Front 95

A cold transmitted by a facial tissue is an example of which form of disease transmission?

Back 95

vehicle transmission

Front 96

A nosocomial infection is

Back 96

acquired during the course of hospitalization.

Front 97

Which of the following does NOT contribute to the emergence of infectious diseases?

Back 97

The emergence of infectious diseases can be attributed to all of these

Front 98

Malaria is an infectious disease caused by infection with a protozoan. In certain tropical regions, malaria is constantly present. We would say that malaria is a(n) _________ disease in these regions.

Back 98

endemic

Front 99

Sulfanilamides interfere with __________.

Back 99

folic acid synthesis in bacteria

Front 100

What is meant when a bacterium is said to become "resistant" to an antibiotic?

Back 100

The bacterium is neither killed nor inhibited by the antibiotic

Front 101

When a patient is treated with antibiotics, __________.

Back 101

the drug will kill or inhibit the growth of all of the sensitive bacterial cells

Front 102

The process of acquiring antibiotic resistance by means of bacteriophage activity is called

Back 102

transduction.

Front 103

Which of the following mutations would not result in antibiotic resistance?

Back 103

Silent mutation

Front 104

R-plasmids are most likely acquired via

Back 104

bacterial conjugation.

Front 105

If penicillin G is chosen as the best treatment for a given infection, what microorganisms are most likely the cause?

Back 105

gram-positive bacteria

Front 106

Why is it more difficult to treat viral infections than it is to treat bacterial infections?

Back 106

Viruses use the host cell's processes to carry out their own reproduction.

Front 107

What is meant by selective toxicity?

Back 107

Chemotherapeutic agents should act against the pathogen and not the host.

Front 108

Why are chemotherapeutic agents that work on the peptidoglycan cell wall of bacteria a good choice of drug?

Back 108

Humans and other animal hosts lack peptidoglycan cell walls.

Front 109

Why is polymyxin only used on the skin?

Back 109

It can also damage living human cell membranes, but the drug is safely used on the skin, where the outer layers of cells are dead.

Front 110

Quinolones and fluoroquinolones act against what bacterial target?

Back 110

DNA gyrase

Front 111

Why is it difficult to find good chemotherapeutic agents against viruses?

Back 111

Viruses depend on the host cell's machinery, so it is hard to find a viral target that would leave the host cell unaffected.

Front 112

Consider a Kirby-Bauer disk-diffusion assay. If you put penicillin and streptomycin disks adjacent to one another, the zone of inhibition is greater than that obtained by either disk alone. This is an example of __________.

Back 112

synergism

Front 113

Which antibiotic is overcome by beta-lactamases?

Back 113

Penicillin

Front 114

How might efflux pumps increase antibiotic resistance in bacteria?

Back 114

Resistant bacteria can have more efflux pumps, and can have less specific efflux pumps

Front 115

Bacteria that are resistant to sulfonamide have enzymes that have a greater affinity for what?

Back 115

PABA

Front 116

Why would an efflux pump for penicillin located on a bacterial cell membrane not be effective at providing resistance to the drug?

Back 116

Penicillin disrupts the cell wall, which is located outside of the cell membrane.

Front 117

Membrane transport proteins are required for which mode(s) of antibiotic resistance?

Back 117

Efflux pumps, beta-lactamases, and modification of porins all utilize membrane transport proteins.

Front 118

Certain cancer cells have ABC transport molecules at the cell surface. These transporters use energy from ATP to move chemotherapeutic agents out of the cell. Which of the following do you think these transporters are most closely related to?

Back 118

membrane pumps

Front 119

A researcher creates an antibiotic that binds to a protein present only on B. anthracis (the causative agent of anthrax), lysing the cell from the outside. After a couple of years using this antibiotic, some resistant organisms are found. Which of the following best outlines the mechanism for development of this resistance?

Back 119

mutation in B. anthracis → altered target → resistant bacterium

Front 120

A new bacterial molecule is discovered. This molecule binds to an antibiotic and facilitates the binding of a phosphate group, thus inactivating the antibiotic. Which category best describes the mechanism of antibiotic resistance conferred by this molecule?

Back 120

bacterial enzymes

Front 121

How do antifungal drugs such as miconazole and amphotericin B function?

Back 121

by disrupting the plasma membrane

Front 122

Why is methicillin-resistant Staphylococcus aureus (MRSA) methicillin resistant?

Back 122

It produces a modified version of the molecule that is targeted by the drug.

Front 123

Which of the following is an antiprotozoan drug that interferes with anaerobic metabolism?

Back 123

metronidazole

Front 124

Why is it more difficult to treat viral infections than it is to treat bacterial infections?

Back 124

Viruses use the host cell's processes to carry out their own reproduction.

Front 125

Consider a Kirby-Bauer disk-diffusion assay. If you put penicillin and streptomycin disks adjacent to one another, the zone of inhibition is greater than that obtained by either disk alone. This is an example of __________.

Back 125

synergism

Front 126

Protozoan and helminthic diseases are difficult to treat because

Back 126

their cells are structurally and functionally similar to human cells.

Front 127

Which of the following antimicrobial agents has the fewest side effects?

Back 127

penicillin

Front 128

Sulfanilamides interfere with __________

Back 128

folic acid synthesis in bacteria

Front 129

A drug that inhibits mitosis, such as griseofulvin, would be more effective against

Back 129

fungi.

Front 130

Which of the following methods of action would be bacteriostatic?

Back 130

inhibition of protein synthesis

Front 131

Which of the following antibiotics is NOT bactericidal?

Back 131

polyenes

Front 132

The antimicrobial drugs with the broadest spectrum of activity are

Back 132

tetracyclines.

Front 133

In what way are semisynthetic penicillins and natural penicillins alike?

Back 133

Both are based on β-lactam.

Front 134

The following data were obtained from a broth dilution test.

Concentration of Antibiotic XGrowthGrowth in
Subculture

2 μg/ml++

10 μg/ml-+

15 μg/ml--

25 μg/ml--

In the table, the minimal inhibitory concentration of antibiotic X is

Back 134

10 μg/ml.

Front 135

Use of antibiotics in animal feed leads to antibiotic-resistant bacteria because

Back 135

the antibiotics kill susceptible bacteria, but the few that are naturally resistant live and reproduce, and their progeny repopulate the host animal.

Front 136

More than half of our antibiotics are

Back 136

produced by bacteria.

Front 137

A drug binds to the ribosome as shown in the figure. The effect is to

Back 137

prevent transcription

Front 138

PABA serves as the competitive inhibitor in the action of sulfanilamides.

Back 138

False