Viruses MCQs With Answer is a focused resource for B. Pharm students preparing for exams in virology, pharmacology and clinical microbiology. This concise, keyword-rich introduction covers viral structure, replication cycles, classification (Baltimore system), pathogenesis, diagnostic methods, antiviral mechanisms and vaccine principles, emphasizing pharmacological relevance. Designed to enhance retention, the MCQs highlight drug targets, resistance, and clinically important viruses like influenza, HIV, hepatitis and herpesviruses. Each question reinforces core concepts needed for therapeutics and lab interpretation. Clear explanations and repeated practice improve recall and exam performance. Now let’s test your knowledge with 50 MCQs on this topic.
Q1. Which structure is composed of repeating protein subunits called capsomeres?
- Envelope
- Nucleocapsid
- Capsid
- Genome
Correct Answer: Capsid
Q2. Which classification system groups viruses by genome type and replication strategy?
- Taxonomic nomenclature
- Baltimore classification
- Phylogenetic grouping
- Serotyping
Correct Answer: Baltimore classification
Q3. Single-stranded positive-sense RNA viruses can be directly translated by host ribosomes because their genome acts as:
- Template for DNA synthesis
- mRNA
- Antigen
- Reverse transcriptase
Correct Answer: mRNA
Q4. Which enzyme is essential for retroviruses to synthesize DNA from RNA?
- RNA-dependent RNA polymerase
- Reverse transcriptase
- DNA polymerase III
- Integrase
Correct Answer: Reverse transcriptase
Q5. Which viral component determines host cell specificity and entry?
- Capsomere composition
- Viral envelope glycoproteins
- Genome length
- Viral proteases
Correct Answer: Viral envelope glycoproteins
Q6. Antigenic drift in influenza viruses is primarily due to:
- Reassortment of genome segments
- Point mutations in surface proteins
- Acquisition of host genes
- Loss of envelope
Correct Answer: Point mutations in surface proteins
Q7. Antigenic shift differs from drift because shift involves:
- Slow accumulation of point mutations
- Reassortment of segmented genomes
- Increased fidelity of polymerase
- Host immune suppression
Correct Answer: Reassortment of segmented genomes
Q8. Which diagnostic test amplifies viral nucleic acid for detection?
- ELISA
- PCR
- Electron microscopy
- Hemagglutination
Correct Answer: PCR
Q9. Which antiviral drug class inhibits viral neuraminidase in influenza?
- Nucleoside analogs
- Neuraminidase inhibitors
- Protease inhibitors
- Fusion inhibitors
Correct Answer: Neuraminidase inhibitors
Q10. Acyclovir is effective against herpesviruses because it is activated by:
- Host cell thymidine kinase
- Viral thymidine kinase
- Viral protease
- RNA polymerase
Correct Answer: Viral thymidine kinase
Q11. Which virus is a common cause of viral hepatitis and can integrate into host DNA?
- Hepatitis A virus
- Hepatitis B virus
- Hepatitis E virus
- Rota virus
Correct Answer: Hepatitis B virus
Q12. Which viral genome type is packaged by parvoviruses?
- Double-stranded DNA
- Single-stranded DNA
- Single-stranded RNA positive sense
- Double-stranded RNA
Correct Answer: Single-stranded DNA
Q13. Viral uncoating refers to:
- Attachment to the host cell
- Release of the viral genome into the host
- Assembly of new virions
- Exit of virions by lysis
Correct Answer: Release of the viral genome into the host
Q14. Which property makes enveloped viruses more sensitive to detergents?
- Rigid capsid
- Lipid bilayer envelope
- Double-stranded genome
- DNA-dependent polymerase
Correct Answer: Lipid bilayer envelope
Q15. Which enzyme do RNA viruses typically use to replicate their genome?
- DNA-dependent RNA polymerase
- RNA-dependent RNA polymerase
- Reverse transcriptase
- DNA ligase
Correct Answer: RNA-dependent RNA polymerase
Q16. Live attenuated vaccines are characterized by:
- Inactivated viral particles
- Weakened but replication-competent virus
- Only viral proteins
- Viral DNA fragments
Correct Answer: Weakened but replication-competent virus
Q17. Which viral family includes poliovirus and rhinovirus?
- Herpesviridae
- Picornaviridae
- Orthomyxoviridae
- Retroviridae
Correct Answer: Picornaviridae
Q18. Which process describes viral assembly of new particles inside a host cell?
- Penetration
- Replication
- Assembly
- Translation
Correct Answer: Assembly
Q19. Which virus family contains segmented negative-sense RNA genomes like influenza?
- Paramyxoviridae
- Picornaviridae
- Orthomyxoviridae
- Flaviviridae
Correct Answer: Orthomyxoviridae
Q20. Which antiviral drug class inhibits HIV protease to prevent maturation?
- Protease inhibitors
- Integrase inhibitors
- Reverse transcriptase inhibitors
- Fusion inhibitors
Correct Answer: Protease inhibitors
Q21. A viral tropism is best defined as:
- Rate of mutation
- Range of host cells a virus can infect
- Length of viral genome
- Type of capsid symmetry
Correct Answer: Range of host cells a virus can infect
Q22. Which diagnostic assay detects viral antigens using antibodies?
- PCR
- ELISA
- Northern blot
- Cell culture plaque assay
Correct Answer: ELISA
Q23. Which virus is known for causing latent infections that can reactivate later?
- Norovirus
- Herpes simplex virus
- Rhinovirus
- Adenovirus
Correct Answer: Herpes simplex virus
Q24. Which viral particle is non-enveloped and highly stable in the environment?
- Influenza virus
- Poliovirus
- HIV
- Hepatitis B virus
Correct Answer: Poliovirus
Q25. Viral budding from the host cell typically acquires which structure?
- Capsid only
- Lipid envelope derived from host membrane
- Cell wall components
- Ribosomal subunits
Correct Answer: Lipid envelope derived from host membrane
Q26. Which hepatitis virus is primarily transmitted through the fecal-oral route?
- Hepatitis B
- Hepatitis C
- Hepatitis A
- Hepatitis D
Correct Answer: Hepatitis A
Q27. Which viral protein is targeted by neuraminidase inhibitors like oseltamivir?
- Hemagglutinin
- Neuraminidase
- M2 ion channel
- Reverse transcriptase
Correct Answer: Neuraminidase
Q28. Which virus family includes HIV?
- Herpesviridae
- Retroviridae
- Flaviviridae
- Coronaviridae
Correct Answer: Retroviridae
Q29. Viral latency means the virus:
- Is cleared completely
- Persists in a dormant state within host cells
- Causes immediate cell lysis
- Constantly replicates at high levels
Correct Answer: Persists in a dormant state within host cells
Q30. Which technique measures viral infectivity by counting plaques?
- Plaque assay
- PCR
- ELISA
- Western blot
Correct Answer: Plaque assay
Q31. Which viral enzyme integrates viral DNA into the host genome in retroviruses?
- Reverse transcriptase
- Integrase
- Protease
- RNA polymerase
Correct Answer: Integrase
Q32. Which characteristic is typical of dsRNA viruses like rotavirus?
- Genome segmented and double-stranded RNA
- Integrates into host genome
- Has an envelope
- Replicates in nucleus only
Correct Answer: Genome segmented and double-stranded RNA
Q33. Which viral vaccine type contains only selected viral proteins or peptides?
- Live attenuated vaccine
- Inactivated whole-virus vaccine
- Subunit vaccine
- Replicating viral vector vaccine
Correct Answer: Subunit vaccine
Q34. Viral zoonosis refers to infections:
- Transmitted only between humans
- Acquired from animal reservoirs
- Caused by bacteria
- Restricted to laboratory settings
Correct Answer: Acquired from animal reservoirs
Q35. Which antiviral inhibits HIV reverse transcriptase as a nucleoside analog?
- Ritonavir
- Lamivudine
- Oseltamivir
- Acyclovir
Correct Answer: Lamivudine
Q36. Viral hemagglutination assay detects virus by:
- Ability to lyse red blood cells
- Ability to agglutinate red blood cells
- Inhibiting neuraminidase
- Binding to antibodies only
Correct Answer: Ability to agglutinate red blood cells
Q37. Which virus is RNA-based and causes dengue fever?
- Flavivirus
- Orthomyxovirus
- Paramyxovirus
- Herpesvirus
Correct Answer: Flavivirus
Q38. Which antiviral drug blocks HIV entry by binding CCR5 co-receptor?
- Maraviroc
- Zidovudine
- Ritonavir
- Enfuvirtide
Correct Answer: Maraviroc
Q39. Viral recombination refers to:
- Exchange of genetic material between related viruses
- Only point mutations
- Loss of viral envelope
- Viral protein degradation
Correct Answer: Exchange of genetic material between related viruses
Q40. Which viral structure symmetry is common in many bacteriophages?
- Helical symmetry
- Icosahedral symmetry
- Filamentous symmetry
- No symmetry
Correct Answer: Icosahedral symmetry
Q41. Which test distinguishes between recent and past infection by measuring IgM vs IgG?
- Viral culture
- Serology
- PCR
- Electron microscopy
Correct Answer: Serology
Q42. Which viral family includes SARS-CoV-2?
- Paramyxoviridae
- Flaviviridae
- Coronaviridae
- Picornaviridae
Correct Answer: Coronaviridae
Q43. Which mechanism commonly causes antiviral drug resistance?
- Host cell mutation
- Viral genome mutation altering drug target
- Increased drug absorption
- Changes in patient diet
Correct Answer: Viral genome mutation altering drug target
Q44. Which viral protein mediates fusion of viral and host membranes in enveloped viruses?
- Capsid protein
- Fusion protein
- Polymerase
- Protease
Correct Answer: Fusion protein
Q45. Which virus is associated with cervical cancer due to oncogenic strains?
- Epstein–Barr virus
- Human papillomavirus
- Hepatitis A virus
- Measles virus
Correct Answer: Human papillomavirus
Q46. Which antiviral used for influenza targets the M2 ion channel?
- Oseltamivir
- Amantadine
- Ribavirin
- Zanamivir
Correct Answer: Amantadine
Q47. Which laboratory safety containment is most appropriate for handling high-risk viral pathogens?
- Biosafety Level 1
- Biosafety Level 2
- Biosafety Level 3 or 4 depending on pathogen
- No containment needed
Correct Answer: Biosafety Level 3 or 4 depending on pathogen
Q48. Viral syncytium formation is caused by:
- Host cell apoptosis only
- Fusion of infected cells mediated by viral proteins
- Rapid cell division
- Neutralizing antibodies
Correct Answer: Fusion of infected cells mediated by viral proteins
Q49. Which antiviral is a broad-spectrum guanosine analog used against RSV and some RNA viruses?
- Ribavirin
- Acyclovir
- Zidovudine
- Oseltamivir
Correct Answer: Ribavirin
Q50. Which viral nucleic acid is directly infectious when introduced into permissive cells without proteins?
- Double-stranded DNA
- Single-stranded negative-sense RNA
- Single-stranded positive-sense RNA
- Double-stranded RNA
Correct Answer: Single-stranded positive-sense RNA

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