ANSC 400 EXAM 3 QUESTIONS WITH VERIFIED ANSWERS
Which of the following sequences does correctly represent the order of events leading
to infection of a CD4+ T cell by HIV infection?
1) gp120 binds to the CD4 receptor on the T cell surface
2) Dentritic cells release HIV virions by exocytosis
3) a conformational change exposes gp41
4) dentritic cells capture HIV via DC-SIGN receptor-mediated endocytosis
5) a conformational change exposes the co-receptor binding site, allowing gp120 to bind
CCR5 or CXCR4 - Answers - 4->2->1->5->3
What happens to CD4+ T cell levels during the asymptomatic phase of HIV infection?
A) CD4+ T cells decline rapidly, leading to immediate immune system collapse
B) CD4+ T cells remain constant throughout this phase
C) CD4+ T cells drop initially and then return permanently to normal levels
D) CD4+ T cells partially recover after the acute phase and then gradually decline over
time - Answers - D
Which of the following describes the primary mechanism by which high risk HPV types
such as HPV 16 and 18, promote oncogenesis?
A) insertional mutagenesis leading to the activation of the cellular src gene
B) the production of the E6 protein, which degrades p53, and the E7 protein which binds
to Rb
C) the induction of chronic inflammation and the subsequent generation of reactive
oxygen species (ROS)
D) the use of the viral Tax transcription factor to prevent the phosphorylation of p53 -
Answers - B
Regarding the discovery of RNA interference (RNAi) what was the significant finding of
the Fire&Mello experiment in 1998?
A) ss"sense" RNA was identified as the only molecule capable of inhibiting translation
B) RNAi was determined to be a natural defense mechanism found only in plants &
fungi
C) dsRNA was found to be orders of magnitude more effective at silencing target genes
than ss RNA
D)The process of gene silencing requires transgenes to be permanently incorporated
into the host genome - Answers - C
T/F Covid 19 is a -ssRNA virus - Answers - False, Covid19 is a +ssRNA virus
Which are the main HIV/AIDS infection and transmission routes?
A) sexual conduct
B) through blood
C) from the mother to child
, D) all of the above
E) none of the above - Answers - D
1 possible route of HIV infection is:?
A) airborne
B) blood
C) ingestion
D) touching - Answers - B
An individual suffers minor scratches with no bleeding following contact with a wild bat.
Given the presumed exposure to rabies, which of the following measures should be
taken?
A) immediate vaccination
B) no prophylaxis measures are required
C) administration of rabies immunoglobulin
D) Both a and c - Answers - C
T/F antivirals can inhibit assembly - Answers - False
T/F When the immune system responds to a pathogen, it is referred to as passive
immunity, while the transfer of immune system components is referred to as active
(acquired) immunity - Answers - False
T/F HPV E6 protein promotes cancer development by binding to and degrading the
tumour suppressor protein p53 - Answers - True
T/F The src oncogene carried by Rous sarcoma virus RSV was originally derived from
the host cells genome, and its viral version is an example of a viral oncogene captured
from a cellular proto-oncogene - Answers - True
A mutation in what gene will likely NOT lead to cancer?
A) oncogenes/ proto-oncogenes
B) DNA repair genes
C) RNA repair genes
D) tumor suppressor genes - Answers - C
What person is most at risk for Kaposi's Sarcoma?
A) a child attending a daycare
B) an AIDS patient
C) a young traveler visiting the southern hemisphere
D) a zookeeper - Answers - B
T/F DNA vaccines are generally approved for use in humans - Answers - F
Which of the following are true regarding viral vector vaccines?
1. Generate a B-cell and T-cell response
Which of the following sequences does correctly represent the order of events leading
to infection of a CD4+ T cell by HIV infection?
1) gp120 binds to the CD4 receptor on the T cell surface
2) Dentritic cells release HIV virions by exocytosis
3) a conformational change exposes gp41
4) dentritic cells capture HIV via DC-SIGN receptor-mediated endocytosis
5) a conformational change exposes the co-receptor binding site, allowing gp120 to bind
CCR5 or CXCR4 - Answers - 4->2->1->5->3
What happens to CD4+ T cell levels during the asymptomatic phase of HIV infection?
A) CD4+ T cells decline rapidly, leading to immediate immune system collapse
B) CD4+ T cells remain constant throughout this phase
C) CD4+ T cells drop initially and then return permanently to normal levels
D) CD4+ T cells partially recover after the acute phase and then gradually decline over
time - Answers - D
Which of the following describes the primary mechanism by which high risk HPV types
such as HPV 16 and 18, promote oncogenesis?
A) insertional mutagenesis leading to the activation of the cellular src gene
B) the production of the E6 protein, which degrades p53, and the E7 protein which binds
to Rb
C) the induction of chronic inflammation and the subsequent generation of reactive
oxygen species (ROS)
D) the use of the viral Tax transcription factor to prevent the phosphorylation of p53 -
Answers - B
Regarding the discovery of RNA interference (RNAi) what was the significant finding of
the Fire&Mello experiment in 1998?
A) ss"sense" RNA was identified as the only molecule capable of inhibiting translation
B) RNAi was determined to be a natural defense mechanism found only in plants &
fungi
C) dsRNA was found to be orders of magnitude more effective at silencing target genes
than ss RNA
D)The process of gene silencing requires transgenes to be permanently incorporated
into the host genome - Answers - C
T/F Covid 19 is a -ssRNA virus - Answers - False, Covid19 is a +ssRNA virus
Which are the main HIV/AIDS infection and transmission routes?
A) sexual conduct
B) through blood
C) from the mother to child
, D) all of the above
E) none of the above - Answers - D
1 possible route of HIV infection is:?
A) airborne
B) blood
C) ingestion
D) touching - Answers - B
An individual suffers minor scratches with no bleeding following contact with a wild bat.
Given the presumed exposure to rabies, which of the following measures should be
taken?
A) immediate vaccination
B) no prophylaxis measures are required
C) administration of rabies immunoglobulin
D) Both a and c - Answers - C
T/F antivirals can inhibit assembly - Answers - False
T/F When the immune system responds to a pathogen, it is referred to as passive
immunity, while the transfer of immune system components is referred to as active
(acquired) immunity - Answers - False
T/F HPV E6 protein promotes cancer development by binding to and degrading the
tumour suppressor protein p53 - Answers - True
T/F The src oncogene carried by Rous sarcoma virus RSV was originally derived from
the host cells genome, and its viral version is an example of a viral oncogene captured
from a cellular proto-oncogene - Answers - True
A mutation in what gene will likely NOT lead to cancer?
A) oncogenes/ proto-oncogenes
B) DNA repair genes
C) RNA repair genes
D) tumor suppressor genes - Answers - C
What person is most at risk for Kaposi's Sarcoma?
A) a child attending a daycare
B) an AIDS patient
C) a young traveler visiting the southern hemisphere
D) a zookeeper - Answers - B
T/F DNA vaccines are generally approved for use in humans - Answers - F
Which of the following are true regarding viral vector vaccines?
1. Generate a B-cell and T-cell response
