1. In which year was ICTV established?
a) 1960
b) 1965
c) 1963
d) 1966
Explanation: The International Committee on Taxonomy of Viruses (ICTV) was established in 1966 as the International Committee on Nomenclature of Viruses, but the name was later renamed to ICTV. It is governed by Statutes approved by the Virology division.
2. Measles virus belong to the family ______________
a) Paramoxyviridae
b) Filoviridae
c) Bunyaviridae
d) Flaviviridae
Explanation: Measles virus belongs to the family Paramoxyviridae in order of Mononegavirales and currently 49 species are placed under this family, divided among seven genera.
3. Satellite viruses do not encode enzymes for replication.
a) True
b) False
Explanation: Neither satellite viruses nor satellite nucleic acids encode for the enzymes that are required for the replication of their genomes. They require helper viruses to provide replicative enzymes.
4. Viruses are larger than prions.
a) True
b) False
Explanation: Viruses are larger than prions. Prions are very smaller than viruses and even smaller than the smallest of the viruses and can be seen only through the electron microscope.
5. 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.
6. Which of the following molecule is used as a receptor by Rhinoviruses?
a) CD4
b) CD25
c) ICAM-1
d) CCR5
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).
7. Which of the following virus does not use the CXCR4 molecule as a receptor?
a) HIV-1
b) HIV-2
c) Poliovirus
d) SIV
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.
8. Which of the following is a type of coreceptor molecule?
a) Heparan sulfate
b) Acetylcholine
c) Phosphatidylserine
d) CR2
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.
9. 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.
10. Which of the following organelle prevents the entry of viruses in plant cells?
a) Mitochondria
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.