Virology Multiple Choice Questions & Answers (MCQs) focuses on “Rhinovirus and Coronavirus”.
1. Which of the following is the cause of a common cold?
a) Herpes virus
b) Rhinovirus
c) Echovirus
d) Coxsackievirus
Answer: b
Clarification: The rhinoviruses are the viruses that cause common cold most frequently. All the age groups are affected and the infection is endemic with higher frequencies during autumn and spring in temperate climates.
2. The rhinovirus cannot be isolated from ____________
a) nose
b) fecal
c) throat
d) sputum
Answer: b
Clarification: The rhinovirus cannot be isolated from fecal as they are not present in fecal matter. They can be isolated from the nose, the throat, and the sputum. Special cell culture techniques are needed for virus isolation and are performed in very few laboratories.
3. The rhinovirus contains _________ as their genome.
a) ssDNA
b) ssRNA
c) dsDNA
d) dsRNA
Answer: b
Clarification: The rhinovirus possesses single-stranded RNA as their genome with positive sense mRNA. This RNA molecule functions directly as a message, encoding a single open reading frame, flanked by untranslated regions (UTRs).
4. The nucleotides of the 5’-UTR forms a _____________
a) root-like structure
b) stem-like structure
c) leaf-like structure
d) spiral structure
Answer: c
Clarification: The nucleotides of the 5’-UTR forms a leaf-like structure that binds viral and hosts proteins forming a nucleoprotein complex required for viral RNA replication. The RNA molecule is directly translated from a type I IRES.
5. The replication of rhinovirus takes place in __________
a) plasma membrane
b) cytoplasm
c) endoplasmic reticulum
d) golgi apparatus
Answer: b
Clarification: The replication of rhinovirus takes place in the cytoplasm. Uncoating and release of the viral RNA into the cytoplasm occurs after acidification of the late endosome.
6. Which of the following is the main portal for HRV entry into the body?
a) Nose
b) Throat
c) Sputum
d) Fecal
Answer: a
Clarification: The nose is the main portal for human rhinovirus (HRV) entry into the body and the primary site of replication is the epithelial surface of the nasal mucosa. The signs of illness are limited to common cold-like symptoms.
7. The group 2a viruses have additional ______________
a) envelope protein
b) nucleocapsid protein
c) structural protein
d) integral membrane glycoprotein
Answer: c
Clarification: The group 2a viruses have an additional structural glycoprotein, the hemagglutinin-esterase protein (425 amino acids). However, this is not essential for replication in vitro and may affect tropism in vivo.
8. Which of the following glycoprotein is the most abundant in virions?
a) S
b) M
c) N
d) E
Answer: b
Clarification: The M glycoprotein is the most abundant protein in virions. Only a small part of M protein protrudes at the surface of the virus. A proportion of M molecules have four transmembrane spanning segments resulting in C-terminus also being exposed on the outer surface of the virus.
9. The common sequence at the beginning of each gene in coronavirus is ____________
a) CUUAACAA
b) CCCUUUAA
c) UUCCAAUU
d) UCUAUAUA
Answer: a
Clarification: The common sequence at the beginning of each gene in coronavirus is CUUAACAA. It is present at the beginning of each gene and is called a transcription regulatory sequence (TRS). The RNA synthesis is attenuated when the polymerase reaches the TRS sequence.
10. The Coronaviruses have double-stranded DNA as their genome.
a) True
b) False
Answer: b
Clarification: The Coronaviruses have single-stranded RNA as their genome. They have the largest RNA genomes comprising 28-32 kilobases of positive sense, ssRNA. The overall organization of the genome is being 5’ UTR – polymerase gene – structural protein genes – 3’ UTR.
11. The S protein in coronavirus is cleaved into seven subunits.
a) True
b) False
Answer: b
Clarification: The S protein in coronavirus is cleaved into two subunits: S1 and S2. S1 is a smaller subunit than S2. However, the functional S protein is highly glycosylated and exists as a trimer.