This set of Virology Interview Questions and Answers for Experienced people focuses on “Process of Viral Infection – 2”.
1. Replicases are used in _______________
Explanation: Replicases are the enzymes used in the replication of the genome. Replicases are usually the Polymerases used in the replication of the RNA genome. They are referred to as replicase to differentiate polymerases involved in transcription.
2. The error rate during RNA replication is approximately _____________
a) 10-5 to 10-7
b) 10-7 to 10-9
c) 10-3 to 10-5
d) 10-1 to 10-3
Explanation: The error rate during RNA virus replication is estimated to be approximately 10-3 to 10-5 per base per genome replication event. This places a limit on the maximum size of an RNA-based genome since as the size of the genome increases the probability of it containing a mutation will also increase.
3. Which of the following component in genetic control encodes a repressor protein of 236 amino acids?
Explanation: The component involved in encoding a repressor protein of 236 amino acids is cI. It is transcribed from its promoter and encodes repressor protein which binds to OR and prevents the transcription of cro protein.
4. An antiterminator protein is encoded by ____________
Explanation: N is a component in genetic control that encodes an antiterminator protein and it acts as an alternative rho (ρ) factor for host-cell RNA polymerase, modifying its activity and permitting extensive transcription from PL and PR.
5. Which of the following RNA Polymerase is insensitive to α-amanitin?
a) Pol II
b) Pol IV
c) Pol III
d) Pol I
Explanation: RNA polymerase I is unaffected or insensitive to α-amanitin. It transcribes ribosomal RNAs. Whereas Pol II is highly sensitive and Pol III is moderately sensitive to α-amanitin.
6. Which of the following is programmed cell death?
Explanation: Apoptosis is also known as programmed cell death. It is a critical mechanism in tissue remodeling during development and in cell killing by the immune system. It is a tightly regulated process.
7. The gene for Interferon-β is located on _______________
a) chromosome 9
b) chromosome 4
c) chromosome 12
d) chromosome 10
Explanation: The single gene for Interferon-β is located on human chromosome 9. The mature protein contains 145 amino acids and is glycosylated with approximately 30% homology to other interferons. It is predominantly synthesized by fibroblasts.
8. The active form of the reverse transcriptase enzyme is a ________________
Explanation: The active form of the reverse transcriptase (RT) enzyme is a dimer. It is formed of two related polypeptides i.e. a heterodimer. RT from avian retrovirus is composed of alpha and beta subunits.
9. Which of the following surface molecule is used by the Coxsackie B virus as a receptor?
b) MHC I
Explanation: Coxsackie adenovirus receptor (CAR) is a surface molecule that is used by the Coxsackie B virus as a receptor. It is a unique protein of unknown function and it is also used by Adenovirus.
10. The gene for Interferon-gamma is located on chromosome 18.
Explanation: The single gene for Interferon-gamma (γ) is located on human chromosome 12. The mature protein contains 146 amino acids and is glycosylated and has very low sequence homology to other interferons.
11. Interferon-α is synthesized by lymphocytes.
Explanation: Interferon-alpha (α) is synthesized predominantly by lymphocytes and all the genes encoding interferon-alpha are located on chromosome 9 and there are about 15 molecular species of interferon-α.
Sanfoundry Global Education & Learning Series – Virology.
To practice all areas of Virology for Interviews, here is complete set of 1000+ Multiple Choice Questions and Answers.