5. A prokaryotic cell may possess each of the following cellular components EXCEPT

A) cell wall

B) ribosomes

C) flagella

D) a nucleus

E) a cell membrane

Answer: D

6. Microbes that live stably in and on the human body are called the

A) human microbiome

B) transient microbiota

C) opportunistic microbiota

D) pathogenic microorganisms

E) virulent microorganisms

Answer: A

7. Which of the following is NOT a domain in the three-domain system?

A) bacteria

B) archaea

C) eukarya

D) animalia

Answer: D

8. A system of classification grouping organisms into 3 domains based on the cellular organization of organisms was devised by

A) Anton van Leewenhoek

B) Carolus Linnaeus

C) Carl Woese

D) Robert Koch

E) Louis Pasteur

Answer: C

9. Fungal infections are studied by

A) mycologists

B) bacteriologists

C) herpetologists

D) parasitologists

E) virologists

Answer: A

10. When our bodies overcome the offensive tactics of a particular microorganism, this is referred to as

A) colonization

B) disease

C) deficiency

D) therapy

E) resistance

Answer: E

11. In Figure 6.1, which line best depicts an obligate anaerobe in the presence of O2?

A) a

B) b

C) c

Answer: C

12. In Figure 6.1, which line shows the growth of an obligate aerobe incubated anaerobically?

A) a

B) b

C) c

Answer: C

13. In Figure 6.1, which line best illustrates the growth of a facultative anaerobe incubated aerobically?

A) a

B) b

C) c

Answer: A

14. The addition of which of the following to a culture medium will neutralize acids?

A) heat

B) pH

C) sugars

D) carbon

E) buffers

Answer: E

15. Salts and sugars work to preserve foods by creating a

A) lower osmotic pressure

B) hypertonic environment

C) hypotonic environment

D) depletion of nutrients

E) lower pH

Answer: B

16. The term aerotolerant anaerobe refers to an organism that

A) is killed by oxygen

B) tolerates normal atmospheric nitrogen gas levels

C) requires less oxygen than is present in air

D) requires more oxygen than is present in air

E) does not use oxygen but tolerates it

Answer: E

17. Most bacteria reproduce by

A) binary fission

B) mitosis

C) fragmentation

D) aerial hyphae

E) budding

Answer: A

18. Figure 6.2 shows a typical bacterial growth curve with the y-axis indicating the log of the number of bacteria and the x-axis indicating time in culture. In the figure, which section shows a growth phase where the number of cells dying equals the number of cells dividing?

A) a

B) d

C) c

D) a and c

E) b

Answer: C

19. Figure 6.2 shows a typical bacterial growth curve with the y-axis indicating the log of the number of bacteria and the x-axis indicating time in culture. In the figure, which sections of the graph illustrate a logarithmic change in cell numbers?

A) a and c

B) b and d

C) a and d

D) a and b

E) c and d

Answer: B

20. In Figure 6.3, which tube shows the expected growth pattern for a microaerophile?

A) e

B) c

C) d

D) a

E) b

Answer: A

21. Which of the following places the steps of the Gram stain in the correct order?

1-Alcohol-acetone

2-Crystal violet

3-Safranin

4-Iodine

A) 4-3-2-1

B) 2-1-4-3

C) 2-4-1-3

D) 1-2-3-4

Answer: C

22. The purpose of a mordant in the Gram stain is to:

A) make the flagella invisible

B) prevent the crystal violet from leaving the cells

C) remove the simple stain

D) make gram-negative cells visible

Answer: B

23. Which of the following places the steps in the correct sequence?

1-Staining

2-Making

3-Fixing

A) 1-2-3

B) The order is unimportant

C) 2-3-1

D) 1-3-2

Answer: C

24. Simple staining is often necessary to improve contrast in which microscope?

A) electron microscope

B) fluorescence microscope

C) compound light microscope

D) phase-contrast microscope

Answer: C

25. This microscope produces an image of a light cell against a dark background; internal structures are NOT visible.

A) electron microscope

B) darkfield microscope

C) compound light microscope

D) fluorescence microscope

Answer: B

26. Which of the following is never useful for observing living cells?

A) scanning electron microscope

B) darkfield microscope

C) brightfield microscope

D) scanning acoustic microscope

Answer: A

27. Which microscope is most useful for visualizing a biofilm?

A) fluorescence microscope

B) compound light microscope

C) transmission electron microscope

D) scanning acoustic microscope

Answer: D

28. Which step in the Gram stain is the critical step in differentiating gram-positive cells from gram-negative cells?

A) safranin

B) iodine

C) alcohol-acetone

D) crystal violet

Answer: C

29. Which microscope is best used for observing the surfaces of intact cells and viruses?

A) scanning electron microscope

B) phase-contrast microscope

C) brightfield microscope

D) fluorescence microscope

Answer: A

30. Bacterial smears are fixed before staining to

A) make their walls permeable

B) accept stain

C) affix the cells to the slide

D) make the cells visible

Answer: C

31. Which of the following is the best method to sterilize heat-labile solutions?

A) pasteurization

B) autoclave

C) dry heat

D) membrane filtration

Answer: D

32. Which of the following best describes the pattern of microbial death?

A) Not all of the cells in a culture are killed.

B) The pattern varies depending on the antimicrobial agent.

C) The cells in a population die at a constant rate.

D) All the cells in a culture die at once.

E) The pattern varies depending on the species.

Answer: C

33. Which of the following pairs of terms is mismatched?

A) sterilant - destroys all living microorganisms

B) bacteriostatic - kills vegetative bacterial cells

C) germicide - kills microbes

D) virucide - inactivates viruses

E) fungicide - kills yeasts and molds

Answer: B

34. Which of the following does NOT achieve sterilization?

A) ethylene oxide

B) supercritical fluids

C) autoclave

D) pasteurization

E) dry heat

Answer: D

35. An agent used to reduce the number of bacteria on a toilet would most accurately be called a(n)

A) aseptic

B) antiseptic

C) virucide

D) fungicide

E) disinfectant

Answer: E

36. Which of the following methods is used to preserve food by showing the metabolic processes of foodborne microbes?

A) freezing

B) pasteurization

C) nonionizing radiation

D) lyophilization

E) ionizing radiation

Answer: A

37. All of the following factors contribute to hospital-acquired infections EXCEPT

A) some bacteria metabolize disinfectants.

B) invasive procedures can provide a portal of entry for bacteria.

C) None of the answers is correct; all of these factors may contribute to hospital-acquired infections.

D) gram-negative bacteria are often resistant to disinfectants.

Answer: C

38. In Table 7.1, which compound was the most effective against Staphylococcus?

A) D

B) A

C) C

D) The answer cannot be determined based on the information provided.

E) B

Answer: C

39. In Table 7.1, which compound was the most effective against E. coli?

A) C

B) The answer cannot be determined based on the information provided.

C) A

D) B

E) D

Answer: B

40. In Table 7.2, which preservative is most effective?

A) no preservative

B) sodium benzoate

C) potassium sorbate + sodium benzoate

D) potassium sorbate

Answer: C

41. Which of the following organelles most closely resembles a prokaryotic cell?

A) mitochrondrion

B) cell wall

C) vacuole

D) nucleus

Answer: A

42. Functions of the glycocalyx include all of the following EXCEPT

A) binary fission

B) protection against dehydration

C) source of nutrition

D) biofilm formation

Answer: A

43. Which of the following is NOT found or observed to occur in both mitochondria and prokaryotes?

A) cell wall

B) 70S ribosomes

C) ATP-generating mechanism

D) binary fission

Answer: A

44. Which of the following statements is correct about passive diffusion?

A) It involves movement of molecules down a concentration gradient and may require a transport protein.

B) It may require a transport protein.

C) It is a process in which molecules move from a region of lower concentration to one of higher concentration (or up a concentration gradient).

D) It requires an expenditure of energy by the cell.

Answer: A

45. The DNA found in most bacterial cells

A) is circular in structure

B) is linear in structure

C) is surrounded by a nuclear membrane

D) utilizes histones for chromosomal packaging

Answer: A

46. Cells may frequently find themselves in an environment with very low extracellular concentrations of substances needed in higher amounts inside the cell. To obtain these needed items, such cells would be most likely to engage in

A) active transport

B) osmosis

C) facilitated diffusion

D) simple diffusion

Answer: A

47. Where are phospholipids most likely found in a eukaryotic cell?

A) the plasma membrane and organelles

B) ribosomes

C) the plasma membrane

D) metachromatic granules

Answer: A

48. Which of the following statements is TRUE?

A) Endospores allow a cell to survive environmental changes by producing a dormant period with no growth.

B) Endospores are easily stained in a Gram stain.

C) A cell produces one endospore and keeps growing

D) Endospores are for reproduction.

Answer: A

49. Which structure protects bacteria from being phagocytized?

A) capsule

B) cell membrane

C) cell wall

D) slime layer

Answer: A

50. The terms "run" and "tumble" are generally associated with:

A) taxic movements of the cell in response to attractants or repellents.

B) cell wall fluidity.

C) clustering properties of certain rod-shaped bacteria.

D) cell membrane synthesis.

Answer: A

51. A clear area against a confluent "lawn" of bacteria is called a

A) plaque

B) phage

C) cell lysis

D) rash

Answer: A

52. Which of the following is necessary for replication of a prion?

A) PrPSc

B) RNA

C) DNA polymerase

D) DNA

Answer: A

53. A persistent infection is one in which

A) the disease process occurs gradually over a long period.

B) host cells are gradually lysed.

C) host cells are transformed.

D) viral replication is unusually slow.

Answer: A

54. An infectious protein is a

A) prion

B) retrovirus

C) viroid

D) bacteriophage

Answer: A

55. An example of a latent viral infection is

A) cold sores

B) influenza

C) mumps

D) smallpox

Answer: A

56. Which of the following statements about viruses is FALSE?

A) Viruses use their own catabolic enzymes.

B) Viruses have genes.

C) Viruses contain a protein coat.

D) Viruses contain DNA or RNA but never both.

Answer: A

57. Some viruses, such as human herpesvirus 1, infect a cell without causing symptoms. These are called

A) latent viruses

B) lytic viruses

C) phages

D) slow viruses

Answer: A

58. Oncogenic viruses

A) cause tumors to develop

B) have no effect on the host cell

C) are genetically unstable

D) cause acute infections

Answer: A

59. Shingles is an example of

A) reactivation of latent virus

B) persistent virus

C) transformation

D) meiosis

Answer: A

60. Why do most scientists agree that viruses are nonliving entities?

A) They are not composed of cells.

B) They cause diseases in host cells.

C) They pass through filters.

D) They are composed of relatively simple components.

Answer: A

61. A gene is defined as

A) the RNA product of a transcribed section of DNA

B) a sequence of nucleotides in DNA that codes for a functional product.

C) a sequence of nucleotides in RNA that codes for a functional product.

D) any random segment of DNA.

Answer: B

62. Which of the following pairs is mismatched?

A) DNA polymerase - makes a molecule of DNA from a DNA template.

B) DNA ligase - joins segments of DNA.

C) DNA gyrase - relaxes supercoiling in DNA ahead of the replication fork.

D) RNA polymerase - makes a molecule of RNA from an RNA template.

Answer: D

63. DNA is constructed of

A) two strands of nucleotides running in an antiparallel configuration.

B) two complementary strands of nucleotides bonded A-C and G-T.

C) None of the answers is correct.

D) A single strand of nucleotides with internal hydrogen bonding.

Answer: A

64. Which of the following is NOT a product of transcription?

A) rRNA

B) mRNA

C) tRNA

D) a new strand of DNA

Answer: D

65. An enzyme produced in response to the presence of a substrate is called a(n)

A) inducible enzyme

B) promoter

C) restriction enzyme

D) repressible enzyme

Answer: A

66. Transformation is the transfer of DNA from a donor to a recipient cell

A) y sexual reproduction

B) as naked DNA in solution

C) by crossing over

D) by cell-to-cell contact

Answer: B

67. Genetic change in bacteria can be brought about by

A) transduction

B) conjugation

C) All of the answers are correct.

D) transformation

Answer: C

68. According to the operon model, for the synthesis of an inducible enzyme to occur, the

A) repressor must not be synthesized.

B) repressor must bind to the operator.

C) end-product must not be in excess.

D) substrate must bind to the repressor

Answer: D

69. Refer to Table 8.2, the anticodon for valine is

A) CUU

B) CAA

C) GTA

D) CTT

Answer: B

70. Refer to 8.2. If an indeterminate frameshift mutation occurred (that is, one at a random location) in the sequence of bases shown below, what would be the sequence of amino acids coded for?

3' ATTACGCTTTGC 5'

A) leucine-arginine-lysine-alanine

B) The answer cannot be determined based on the information provided.

C) asparagine-cytesine-valine-serine

D) asparagine-arginine-lysine-alanine

Answer: B

71. Conjugation differs from reproduction because conjugation

A) transcribes DNA to RNA.

B) replicates DNA.

C) transfers DNA horizontally, to nearby cells without those cells undergoing replication.

D) copies RNA to make DNA.

Answer: C

72. The necessary ingredients for DNA synthesis can be mixed together in a test tube. The DNA polymerase is from Thermus aquaticus, and the template is from a human cell. The DNA synthesized would be most similar to

A)aquaticus DNA

B) a mixture of human and aquaticus DNA

C) human DNA

D) human RNA

Answer: C

73. If you knew the sequence of nucleotides within a gene, which one of the following could you determine with the most accuracy?

A) the tertiary structure of the protein

B) the secondary structure of the protein

C) the quarternary structure of the protein

D) the primary structure of the protein

Answer: D

74. An enzyme that copies DNA to make a molecule of RNA is

A) DNA ligase

B) RNA polymerase

C) DNA helicase

D) DNA polymerase

Answer: B

75. When two genes from two different people are sequenced and aligned, it is discovered that there are multiple sequence differences in the coding segment DNA level. However, when the proteins formed by genes have their amino acids sequenced, there is no difference observed between the two. What is the most likely explanation for this observation?

A) Mutations at the DNA level are not reflected in proteins produced.

B) The mutations are repaired at the mRNA level after transcription has occurred, but before translation.

C) The mutations lie at locations where they don't affect protein sequence due to degeneracy of the genetic code.

D) RNA processing removes the different segments from the mRNA molecules of each person prior to translation.

Answer: C

76. Open-reading frames are segments of DNA in which both start and stop codons are found.

A) True

B) False

Answer: A

77. Bacteria usually contain multiple chromosomes.

A) True

B) False

Answer: B

78. Both base substitution and frameshift mutations can result in the formation of premature stop codons.

A) True

B) False

Answer: A

79. In the Ames test, any colonies that form on the control plates, in the absence of chemical being tested, should be the result of spontaneous mutations.

A) True

B) False

Answer: A

80. Cell-to-cell contact is required for transduction to occur.

A) True

B) False

Answer: B

81. Most of the available antimicrobial agents are effective against

A) bacteria

B) protozoa

C) viruses

D) fungi

Answer: A

82. In Table 20.1, as illustrated by the data shown, the minimal bactericidal concentration of antibiotic X is: (note: subculture means they grow again from the growth column in this case)

A) 25 ug/mL

B) The answer cannot be determined based on the information provided.

C) 15 ug/mL

D) 10 ug/mL

Answer: C

83. In Table 20.1, the minimal inhibitory concentration of antibiotic X is

A) 15 ug/mL

B) The answer cannot be determined based on the information provided.

C) 25 ug/mL

D) 10 ug/mL

Answer: D

84. From the data in Table 20.1, you can predict that the effect of the drug on a different microbe

A) will be the same.

B) can't be predicted from the information provided.

C) will be weaker.

D) will be stronger.

Answer: B

85. More than half of our antibiotics are

A) synthesized in laboratories.

B) produced by eukaryotic organisms.

C) produced by bacteria.

D) produced by Fleming.

Answer: C

86. Which of the following statements about drug resistance is FALSE?

A) It may be carried on a plasmid

B) It may be due to enzymes that degrade some antibiotics

C) It may be due to decreased uptake of a drug

D) It is found only in gram-negative bacteria

Answer: D

87. Drug resistance occurs

A) because bacteria are normal microbiota

B) when antibiotics are used indiscriminately

C) when antibiotics are taken after the symptoms disappear

D) against antibiotics and not against synthetic chemotherapeutic agents

Answer: B

88. In Table 20.2, the most effective antibiotic tested was

A) A

B) B

C) C

D) D

E) The answer cannot be determined based on the information provided.

Answer: D

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

A) the antibiotics persist in soil and water

B) the antibiotics cause new mutations to occur in the surviving bacteria, which results in resistance to antibiotics.

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

D) bacteria from other animals replace those killed by the antibiotics

Answer: C

90. Community acquired MRSA is typically less virulent than healthcare-associated MRSA.

A) True

B) False

Answer: B

91. A population of cells carrying a desired plasmid is called a

A) clone

B) vector

C) Southern blot

D) PCR

Answer: A

92. Which enzyme would cut this strand of DNA?

GCATGGATCCCAATGC

A) A-BamHI

B) B-EcoRI

C) No answer text provided.

D) C-HaeIII

Answer: A

93. Which of the following places the steps in the PCR procedure in the correct order?

1. Incubate at 94C to denature DNA strands

2. Incubate at 72C for DNA synthesis

3. Incubate at 60C for primer hybridization

A) 1, 3, 2

B) 2, 1, 3

C) 1, 2, 3

D) 3, 1, 2

Answer: A

94. A source of heat-stable DNA polymerase is

A) Thermus aquaticus

B) Saccharomyes cerevisiae

C) Bacillus thuringiensis

D) human

Answer: A

95. Biotechnology involves the

A) use of microorganisms to make desired products, the use of animal cells to make vaccines, and the development of disease-resistant crop plants

B) use of microorganisms to make desired products and the use of animal cells to make vaccines

C) development of disease-resistant crop plants

D) use of animal cells to make vaccines

Answer: A

96. Which of the following is NOT a desired characteristic of DNA vectors used in gene cloning procedures?

A) large size

B) has a selectable marker

C) self-replication

D) may replicate in several species

Answer: A

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

A) direct selection possible

B) the recombinant cell dangerous

C) the recombinant cell unable to survive

D) All of the answers are correct

Answer: A

98. Choose the best pair to complete the following sentence. While _____ is/are responsible for the diversity of life, ______ is/are responsible for shaping a population with organisms possessing characteristics that enhance survival

A) mutations; selection

B) selection; mutations

C) properties; vectors

D) microbes; DNA

Answer: A

99. In recombinant DNA technology, a vector is a self-replicating segment of DNA, such as a plasmid or viral genome.

A) True

B) False

Answer: A

100. What percentage of patients with whooping cough die?

A) 1%

B) 10%

C) 4%

D) 3%

Answer: A

101. What doctor demonstrated that cowpox infection prevented smallpox?

Edward Jenner

102. What stopped the measles virus from spreading throughout New York?

A) antibiotics

B) doctor interventions

C) hand sanitizer

D) herd immunity

Answer: D

103. Autism is most likely caused by ______.

A) genetic

B) vaccine

C) vitamins

D) food

Answer: A

104. The HPV vaccine can prevent

A) whooping cough

B) mumps

C) cancer

D) measles

Answer: C

105. All of the following diseases that were largely eradicated in the US a generation ago are returning EXCEPT:

A) diptheria

B) mumps

C) pertussis

D) measles

Answer: A

106. What percent of parents in the US vaccinate their children?

A) 90%

B) 50%

C) 10%

D) 60%

Answer: A

107. How many people without immunity of the disease will get the measles if exposed to it?

A) 10%

B) 70%

C) 65%

D) 90%

Answer: D

108. Once infected with measles, it is likely you will be infected again.

A) True

B) False

Answer: B

109. Briefly, would you say that vaccination is different from other types of personal health decisions? If so, how?

I think it's no different from other types of personal health decisions. People have the option to say "yes" or "no" if they want to take the vaccine. Just like any other personal health decision, there are pros and cons that people weigh when they make a decision if they want the vaccination or not.

110. You can catch ebola from sitting near someone on a plane.

A) True

B) False

Answer: B

111. _____ are most likely the natural reservoir for Ebola virus.

Bats

112. What is the biggest risk factor for infection with Ebola?

A) Nursing a patient at home

B) Working in a category IV laboratory

C) Going grocery shopping

D) Attending football matches or large gatherings

Answer: A

113. An animal disease transmissible to humans is called

A) zoonosis

B) spillover

C) amplifier

D) pandemic

Answer: A

114. An organism that carries the pathogen while suffering little to no illness is called

A) reservoir host

B) carrier

C) fomite

D) all of the aboce

Answer: A

115. What is the treatment for Zika fever?

A) There is no specific treatment.

B) use of antiviral

C) antibiotics

D) blood transfusion

Answer: A

116. How is Zika transmitted?

It is transmitted to people primarily through the bite of mosquitos. (but can spread through sex and from a pregnant woman to her fetus)

117. What is a spillover event?

Occurs when a reservoir population with a high pathogen prevalence comes into contact with a novel host population

118. Which of the following statements about healthcare associated infections is FALSE?

A) They may be caused by opportunists.

B) They may be caused by drug resistant bacteria.

C) They occur in compromised patients.

D) The patient was infected before hospitalization.

Answer: D

119. A healthcare-associated infection (traditionally known as a nosocomial infection) is

A) always caused by pathogenic bacteria

B) acquired during the course of hospitalization

C) always caused by medical personnel

D) only a result of surgery

Answer: B

120. The major significance of Robert Koch's work is that?

A) diseases can be transmitted from one animal to another

B) microorganisms are the result of disease

C) microorganisms cause disease

D) microorganisms are present in a diseased animal.

Answer: C

121. Biological transmission differs from mechanical transmission in the biological transmission?

A) involves fomites

B) involves the reproduction of a pathogen in an arthropod vector prior to transmission

C) works only with noncommunicable diseases

D) requires direct contact

Answer: B

122. Which of the following definitions is INCORRECT?

A) sporadic: a disease that affects a population occasionally

B) pandemic: a disease that affects a large number of people in the world in a short time

C) incidence: number of new cases of a disease

D) epidemic: a disease that is constantly present across the world

Answer: D

123. The rise in herd immunity amongst a population can be directly attributed to

A) vaccinations

B) antibiotic-resistant microorganisms

C) improved handwashing

D) None of the answers is correct.

Answer: A

124. Transient microbiota differ from normal microbiota in that transient microbiota

A) never cause disease

B) are found in a certain location on the host

C) are always acquired by direct contact

D) are present for a relatively short time

Answer: D

125. Which of the following is NOT a communicable disease?

A) malaria

B) AIDS

C) Covid-19

D) tetanus

Answer: D

126. Which of the following is NOT a reservoir of infection?

A) none of the answers is correct; all of these can be reservoirs of infection

B) a sick animal

C) a hospital

D) a healthy person

Answer: A

127. Which of the following is a fomite?

A) insects

B) droplets from a sneeze

C) water

D) a hypodermic needle

Answer: D

128. The entry, establishment, and multiplication of a pathogen in a host is called

A) exposure

B) infection

C) inflammation

D) disease

Answer: B

129. Which one of the following is an example of an indirect method of disease transmission?

A) eating contaminated food

B) sneezing

C) coughing

D) shaking hands

Answer: A

130. True or False? Direct methods for the transmission of disease include hand contact and contact with animals?

A) true

B) false

Answer: A

131. Endotoxins are released when:

A) the host is injured during an infection

B) bacterial pathogens leave through a portal of exit

C) ram-negative bacterial cells disintegrate

D) an infection occurs in the body

Answer: C

132. Which of the following microbes would be considered avirulent?

A) Neisseria meningitidis

B) Vibrio cholerae

C) Lactobacillus lactis

D) Mycobacterium tuberculosis

Answer: C

133. An outbreak is considered to be a more contained:

A) pandemic disease

B) epidemic disease

C) local disease

D) endemic disease

Answer: B

134. True or False? Phagocytosis is a form of adaptive immunity in the body.

A) True

B) False

Answer: B

135. All the following statements apply to antigens, except:

A) antigens trigger the production of antibodies

B) antigens are unique chemical groups that are not normally present in the body

C) antigens contain recognizable epitopes

D) antigens are part of the innate immune response

Answer: D

136. Where are B cells and T cells "born"?

A) in the blood

B) in the thyroid

C) in the bone marrow

D) in the thymus

Answer: C

137. On average, how long does it take the adaptive immunity response to become fully active to an infecting pathogen?

A) 10 to 14 days

B) 2 to 3 days

C) 18 to 24 days

D) 28 to 30 days

Answer: A