This set of Virology Multiple Choice Questions & Answers (MCQs) focuses on “Process of Viral Infection – 1”.
1. Which of the following forms the terminal moiety of a carbohydrate group of a glycoprotein?
a) N-acetyl cysteine
b) N-acetyl neuraminic acid
c) N-acetyl glucosamine
d) N-acetyl glutamate
Explanation: N-acetyl neuraminic acid forms the terminal moiety of a carbohydrate group of glycoprotein or glycolipid. It is used as a receptor by members of several different families of viruses.
2. Which of the following molecule is used as a receptor by Rhinoviruses?
Explanation: ICAM-1 is the cell surface molecule that is used as a receptor by most of the rhinoviruses but not all. ICAM-1 is the Intracellular Adhesion Molecule – 1, which is also known as CD54 (Cluster of Differentiation 54).
3. Which of the following virus does not use the CXCR4 molecule as a receptor?
Explanation: Poliovirus does not use the CXCR4 molecule as a receptor. It uses a CD155 surface molecule as the receptor. HIV-1, HIV-2, SIV use CXCR4, CCR3, CD4 as the surface receptor molecule.
4. Which of the following is a type of coreceptor molecule?
a) Heparan sulfate
Explanation: Heparan sulfate is a type of coreceptor molecule which is used by animal viruses such as dengue virus, herpes simplex virus, adeno-associated virus, etc. Acetylcholine, CR2, phosphatidylserine are the types of primary receptor molecules.
5. The fusion of ___________ and ____________ occurs during the entry of viral genome into the cell.
a) lipid bilayer and plasma membrane
b) lipid bilayer and cell wall
c) carbohydrate layer and cytoplasm
d) virus and host cell
Explanation: The fusion of lipid bilayer of enveloped virus and the plasma membrane of the cell occurs during the entry of the viral genome into the cell. It occurs at neutral pH or a low pH.
6. Which of the following organelle prevents the entry of viruses in plant cells?
b) Plasma membrane
c) Golgi bodies
d) Cell wall
Explanation: The cell wall that surrounds the plasma membrane of the plant cells prevents the viruses from attaching and entering the cytoplasm of the plant cell. Thus, plants are infected with viruses with the help of vectors that carry the viral genome into the host plant cells.
7. The presence of O-specific side chains makes a cell sensitive to _____________
Explanation: The presence of O-specific side chains makes the cell sensitive to phages such as P22, Felix O, etc. and resistant to phages such as 6SR, Br2, Br60, etc. The absence of O-specific side chains makes the cell resistant to phages such as P22, Felix O, etc. and sensitive to phages such as 6SR, Br2, Br60, etc.
8. Which of the following compound inhibits the entry of the HIV-1 virus?
Explanation: Enfuvirtide is an antiviral compound that prevents or inhibits the attachment and entry of the HIV-1 virus into the host cells. It is an antiretroviral drug and is also known as T-20.
9. The entry of picornaviruses is inhibited by zanamivir.
Explanation: The attachment and entry of picornaviruses are inhibited by pleconaril, which is an antiviral compound that prevents the uncoating of the viral RNA genome.
10. Which of the following protein helps in the removal of primers in SV40 replication?
a) T antigen
b) DNA ligase
c) RNase H
d) RNase A
Explanation: RNase H is an enzyme or protein which helps in the removal of primers in SV40 replication. Its function is to degrade RNA within RNA: DNA hybrid systems. Whereas RNase A degrades the RNA from RNA: RNA hybrids.
11. DNA ligase has the function the same as a fevicol.
Explanation: DNA ligase is an enzyme or protein which joins the ends of DNA molecules, thus acting as a fevicol. It performs many important roles in the replication processes such as connecting Okazaki fragments, sealing repairs in the DNA molecule, etc.
Sanfoundry Global Education & Learning Series – Virology.
To practice all areas of Virology, here is complete set of 1000+ Multiple Choice Questions and Answers.