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
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
Question 3
The substitution of an adenine for a cytosine is a:
- transcription
- transition
- transversion
- translation
Question 4
The ability of the normal flora to outcompete and prevent the attachment of pathogens is called:
- microbial antagonism
- parasitism
- mutualism
- commensalism
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
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
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
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
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
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
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
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
Question 32
The hydrolytic removal of an adenine base from the DNA backbone is termed a(n) ________.
- translocation
- depurination
- tautomeric shift
- deamination
Question 33
The deamination of 5-methyl cytosine converts it into ________.
- uracil
- guanine
- cytosine
- thymine
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.
Question 35
Which of the following mutagenic agents is unlikely to induce a frameshift mutation?
- ethidium bromide
- alkylating agents
- X-rays
- proflavin
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
