Fa25 Bio-Microbiology FINAL EXAM

Question 8

Which of the following is most responsible for the host specificity of a virus?

• The type of nucleic acid it contains
• Interactions between viral surface proteins and host cell surface receptors
• The location of the virus in the body
• The presence of an envelope around the virus

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Question 1

In retroviruses, the genome consists of positive-sense single-stranded RNA which is then converted into _____ by the enzyme _____.

• single-stranded DNA… RNA polymerase
• double-stranded DNA… reverse transcriptase
• negative-sense RNA… transcriptase
• messenger RNA… protease

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Question 3

The substitution of an adenine for a cytosine is a:

• transcription
• transition
• transversion
• translation

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Question 4

The ability of the normal flora to outcompete and prevent the attachment of pathogens is called:

• microbial antagonism
• parasitism
• mutualism
• commensalism

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Question on Transposons

Which of the following statements about transposons is FALSE?

• Transposons are also called transposable elements
• Transposons are prevalent in bacteria but absent in humans
• Inverted repeats are found at each end of a transposon
• Transposons can carry antibiotic resistance genes

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Question on MMR Vaccine

The MMR vaccine is an example of a:

• combination vaccine
• toxoid vaccine
• subunit vaccine
• conjugated vaccine

Question 15

Which of the following is the stimulus for clonal selection of a particular lymphocyte?

• the binding of an antigen to an antigen receptor in a lymphocyte’s membrane
• the polymerization of amino acids to form a specific antibody
• the agglutination of pathogens by antibodies
• the splicing of different exons in the DNA of a lymphocyte
• the attenuation of a pathogen

Answer: the binding of an antigen to an antigen receptor in a lymphocyte’s membrane

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Question 16

Antigens displayed by phagocytes are recognized by which cell possessing complementary receptor proteins?

• plasma cells
• cytotoxic T cells
• Helper T cells
• B cells
• Red blood cells

Answer: Helper T cells

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Question 17

How many polypeptides and antigen binding sites do antibodies contain?

• 2 polypeptides and 4 antigen binding sites
• 4 polypeptides and 4 antigen binding sites
• 2 polypeptides and 2 antigen binding sites
• 4 polypeptides and 2 antigen binding sites
• 1 polypeptide and 1 antigen binding site

Answer: 4 polypeptides and 2 antigen binding sites

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Question 18

Which of the following is NOT an effect of localized vasodilation?

• Redness
• Heat
• Swelling
• Increased blood flow
• Decreased capillary permeability

Answer: Decreased capillary permeability

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Question 19

Edward Jenner found that people who had been infected with cowpox were protected from:

• Chickenpox
• Smallpox
• Influenza
• The Black Plague
• Measles

Answer: Smallpox

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Question 20

Lymphocytes that are ready to respond to a subsequent exposure to an antigen are:

• Memory cells
• Plasma cells
• Stem cells
• Helper T cells
• Effector cells

Answer: Memory cells

Question 13

Herd immunity is best described as

• All these statements are true
• If some people are vaccinated, the disease cannot spread
• If most people are immune, the disease cannot spread easily
• If one person is immune, the disease cannot spread
• If most people are immune, the disease cannot spread easily

Question 14

In a secondary immune response,

• plasma cells and memory cells are made from existing memory cells
• plasma cells and memory cells are made from existing memory cells
• only memory cells are made
• only plasma cells are made
• naive B cells are activated

Question 15

Which of the following does NOT exist as a viral genome?

• Double-stranded DNA
• Single-stranded RNA
• Double-stranded RNA
• Single-stranded DNA
• All of these types exist

Question 16

In the lytic replication cycle, what occurs immediately after the phage attaches to the bacterial cell?

• The phage lyses the cell
• New phages are assembled
• The phage DNA is replicated
• The phage injects its DNA into the cell
• The phage DNA integrates into the host’s chromosome

Question 16

Localized vasodilation is a hallmark of the inflammatory response. Which of the following is NOT a result of localized vasodilation?

• Redness
• Localized swelling
• Inhibition of clotting
• Increased delivery of oxygen and nutrients to the area
• Increased permeability of the blood vessels
• The area is warm to the touch

Question 17

Chronic wasting disease is caused by a/an

• bacterium
• virus
• viroid
• fungus
• prion
• protozoan

Question 18

A typical antibody consists of ___ polypeptide chains and ___ antigen-binding sites.

• 2 … 4
• 4 … 4
• 2 … 2
• 4 … 2
• 1 … 2

Question 19

Jenner’s work with cowpox led to the eventual eradication of

• smallpox
• measles
• cowpox
• influenza
• polio

Question 20

The uptake of naked DNA from the environment by a living recipient cell is

• transformation
• generalized transduction
• conjugation
• specialized transduction
• transcription
• translation

Question 21

Which of the following is TRUE about genetic material?

• DNA is the genetic material of all cellular life
• DNA is the genetic material of many viruses
• Evolution involves genetic change in a population
• Proteins are encoded by genetic material
• RNA is the genetic material of many viruses
• All these statements are TRUE

Question 22

Which of the following involves the transfer of both viral and bacterial DNA from a donor cell to a recipient cell via an incorrectly excised prophage?

• generalized transduction
• transformation
• conjugation
• specialized transduction
• translation

Question 23

Which of the following sequences would likely NOT be a site where a restriction enzyme cuts?

• 5’GAATTC3′
• 5’GGATCC3′
• 5’GATTAC3′
• 5’AAGCTT3′
• 5’CTGCAG3′

Question 24

In what way do B cells differ from other B cells?

• different B cells possess different types of MHC proteins
• different B cells possess different numbers of chromosomes
• different B cells possess different antigen receptor proteins
• different B cells possess different genes for their antigen receptor proteins

Question 25

Following conjugation with an F’ individual, an F- individual becomes

• F-
• F’
• Hfr
• F+
• Hfr’

Question 30

Which of the following does NOT accurately describe a type of viral genome?

• single-stranded DNA
• linear DNA that is able to circularize
• eight nonidentical pieces of single-stranded RNA
• two identical pieces of single-stranded RNA
• double-stranded RNA
• ALL these accurately describe types of viral genomes that actually exist

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Question 31

A/an ________ is possessed by all viruses, whereas a/an ________ is only possessed by some viruses.

• genome… capsid
• envelope… capsid
• capsid… envelope
• capsid… genome
• genome… envelope

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Question 32

The hydrolytic removal of an adenine base from the DNA backbone is termed a(n) ________.

• translocation
• depurination
• tautomeric shift
• deamination

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Question 33

The deamination of 5-methyl cytosine converts it into ________.

• uracil
• guanine
• cytosine
• thymine

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Question 34

Which of the following statements is FALSE?

• A mutation in a gene’s promoter can change the gene’s expression level.
• A mutation in an intron can affect the splicing of the mRNA.
• Mutations in a gene’s coding region always change the amino acid sequence of the encoded protein.
• A mutation in the 3′ UTR can affect the stability of the mRNA.

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Question 35

Which of the following mutagenic agents is unlikely to induce a frameshift mutation?

• ethidium bromide
• alkylating agents
• X-rays
• proflavin

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Question 36

The inactivation of ________ is one of the events commonly associated with cancers.

• tumor suppressor genes
• oncogenes
• proto-oncogenes
• all of the above are correct