ANSWERS 2025 WITH COMPLETE
SOLUTIONS. ACTUAL EXAM GRADED A+.
Shared feature among Coronaviruses? - Correct Answer ->> They all produce a nested set of
subgenomic mRNAs.
True or False: The HE spike of coronaviruses is responsible for fusion of the viral and host membranes.
- Correct Answer ->> False
True or False: Coronaviruses bud at the plasma membrane. - Correct Answer ->> False
Where do CoV bud? - Correct Answer ->> in intermediate compartments (IC) within the cell
True or False: Acute respiratory distress during a SARS infection is likely caused by a cytokine
storm. - Correct Answer ->> True
What is the accepted reservoir host of SARS? - Correct Answer ->> Bats
Which of the following viruses is not a member of the Flaviviridae family?
1. Rotavirus
2. Yellow Fever Virus
3. West Nile Virus
4. Hep C Virus - Correct Answer ->> Rotavirus
Shared feature between flaviviruses and togaviruses? - Correct Answer ->> Many viruses in
both families are arboviruses.
Which of the following statements about viral fusion is incorrect?
- The low pH of the endosome induces a conformational change in the virion that exposes the fusion
peptide.
,- The viral fusion glycoprotein is always the same glycoprotein that binds the host receptor.
- After fusion of the viral membrane with the endosomal membrane, the viral genome is released into
the cytoplasm. - Correct Answer ->> The viral fusion glycoprotein is always the same glycoprotein
that binds the host receptor.
Flaviviruses and togaviruses both generate polyproteins that thread into and out of the ER membrane;
what is the main purpose of this? - Correct Answer ->> To localize the viral glycoproteins in the ER
lumen where they can then move to the Golgi and become glycosylated.
Which feature of togavirus/alphavirus virions is incorrect?
A- They have flower-shaped spikes extending off of the surface.
B- The envelope is icosahedral, but the capsid is disorganized.
C- Each petal associates with one capsid protein underneath the lipid bilayer.
D- Each petal of the flower is comprised of a heterodimer of the two glycoproteins (E1 and E2). -
Correct Answer ->> The envelope is icosahedral, but the capsid is disorganized.
What recruits host translation initiation factors to the 5' end of calicivirus genomes? - Correct Answer
->> The viral VPg protein
How are the norovirus structural proteins synthesized? - Correct Answer ->> They are translated from
a subgenomic mRNA produced late in the replication cycle.
Which of the following features is true regarding norovirus virions?
A- The minor structural protein VP2 resides only inside the virion.
B- They are extremely stable over a broad pH range.
C- The tips of the arches protruding off the surface are the most hypervariable region of the virion.
D- All of these - Correct Answer ->> All of these
What are 3 features of Norovirus virions? - Correct Answer ->> 1. They are extremely stable over a
broad pH range.
2. The tips of the arches protruding off the surface are the most hypervariable region of the virion.
3. The minor structural protein VP2 resides only inside the virion.
, Astroviruses cause what type of disease outcome? - Correct Answer ->> Gastroenteritis
True or False: Noroviruses are capable of being transmitted by insects. - Correct Answer ->> False
Which of the following is NOT a mode of norovirus transmission?
A- Consumption of contaminated shellfish
B- Bite from an infected mosquito
C- Exposure to contaminated fomites (inanimate object, e.g., door knob)
D- Person-to-person transmission - Correct Answer ->> Bite from an infected mosquito
What are 2 examples of Picornaviruses? - Correct Answer ->> Polioviruses & Rhinoviruses
Which of the following is not a picornavirus?
- Poliovirus
- Influenzavirus
- Rhinovirus - Correct Answer ->> Influenzavirus
True or False: The receptor binding-domain of all picornaviruses resides in the protruding domains of
the virion surface, also referred to as the plateaus. - Correct Answer ->> False
True or False: The receptor-binding domain of all picornaviruses resides in the low-lying domains of the
virion surface, also referred to as the valleys. - Correct Answer ->> True
What are the 2 mechanisms by which picornaviruses can release their genomes into the cytoplasm of
target cells? - Correct Answer ->> 1. Formation of pores in the membrane
2. Dissociation of the virion in acidic endosomes following endocytosis
What factor recruits host translation initiation factors to the 5' end of picornavirus genomes to initiate
protein production? - Correct Answer ->> An internal ribosome entry site (IRES)