RNA Viruses Practice Questions
20 free RNA Viruses practice questions for the Microbiology. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
Which of the following RNA viruses possesses a double-stranded, segmented RNA genome?
- A Reoviridae
- B Retroviridae
- C Rhabdoviridae
- D Togaviridae
Correct answer: Reoviridae
Reoviridae, which includes Rotavirus, is unique among RNA viruses for having a double-stranded RNA genome. This genome is also segmented, typically consisting of 10 to 12 segments depending on the genus.
The 'Antigenic Shift' responsible for influenza pandemics is caused by which mechanism?
- A Reassortment of genome segments between strains
- B Accumulation of point mutations in the HA gene
- C Binding of the virus to a new host cell receptor
- D Integration of the viral RNA into the host genome
Correct answer: Reassortment of genome segments between strains
Antigenic shift occurs when two different influenza A viruses infect the same cell and exchange RNA segments. This results in a novel virus with a completely new hemagglutinin or neuraminidase protein to which the population has no immunity.
Which enzyme is essential for the replication of Retroviruses like HIV but is not found in the host cell?
- A RNA-dependent RNA polymerase
- B DNA-dependent DNA polymerase
- C Reverse Transcriptase
- D Integrase
Correct answer: Reverse Transcriptase
Reverse Transcriptase (RT) is an RNA-dependent DNA polymerase that converts the viral single-stranded RNA genome into double-stranded DNA. This step is mandatory before the viral genome can be integrated into the host cell's DNA.
Which of the following viruses is a leading cause of severe gastroenteritis in children and is characterized by a 'wheel-like' appearance under electron microscopy?
- A Rotavirus
- B Norovirus
- C Astrovirus
- D Sapovirus
Correct answer: Rotavirus
Rotavirus derives its name from the Latin 'rota', meaning wheel, due to its distinct round shape with radiating spokes. It is a major cause of dehydrating diarrhea in infants worldwide.
The presence of 'Negri bodies' in neurons is a pathognomonic finding for which viral infection?
- A Rabies
- B Measles
- C Poliomyelitis
- D Mumps
Correct answer: Rabies
Negri bodies are eosinophilic cytoplasmic inclusion bodies found in the Purkinje cells of the cerebellum and pyramidal cells of the hippocampus. They represent aggregates of viral nucleocapsids in patients infected with the Rabies virus.
Which genus of RNA viruses includes the causative agents of Dengue, Zika, and Yellow Fever?
- A Flavivirus
- B Alphavirus
- C Enterovirus
- D Filovirus
Correct answer: Flavivirus
The Flavivirus genus consists of enveloped, positive-sense single-stranded RNA viruses. Most are arthropod-borne (arboviruses) transmitted primarily by Aedes mosquitoes.
Which protein of the SARS-CoV-2 virus is the primary target for neutralizing antibodies and vaccine development?
- A Nucleocapsid (N) protein
- B Membrane (M) protein
- C Spike (S) protein
- D Envelope (E) protein
Correct answer: Spike (S) protein
The Spike protein facilitates viral entry by binding to the ACE2 receptor on host cells. Because of its surface exposure and critical role in infection, it is the primary focus for immune recognition.
Hepatitis C Virus (HCV) is unique among the primary hepatitis viruses because it belongs to which family?
- A Hepadnaviridae
- B Picornaviridae
- C Flaviviridae
- D Hepeviridae
Correct answer: Flaviviridae
HCV is a member of the Flaviviridae family. Unlike Hepatitis A (Picornavirus) or B (Hepadnavirus), HCV frequently results in chronic infection and is primarily transmitted via blood-to-blood contact.
Which of the following is a non-enveloped, positive-sense RNA virus transmitted via the fecal-oral route?
- A Hepatitis B Virus
- B Hepatitis A Virus
- C Influenza Virus
- D Lassa Virus
Correct answer: Hepatitis A Virus
Hepatitis A Virus (HAV) is a picornavirus. Being non-enveloped makes it resistant to detergents, acid, and heat, allowing it to survive the transit through the stomach and spread through contaminated food and water.
The 'bullet-shaped' morphology is characteristic of which virus family?
- A Filoviridae
- B Rhabdoviridae
- C Bunyaviridae
- D Orthomyxoviridae
Correct answer: Rhabdoviridae
Rhabdoviruses, such as the Rabies virus, have a very distinctive bullet-shaped envelope. This shape is formed by the interaction between the helical nucleocapsid and the matrix protein.
Which of the following describes the genome of the Poliovirus?
- A Negative-sense single-stranded RNA
- B Positive-sense single-stranded RNA
- C Double-stranded segmented RNA
- D Ambisense RNA
Correct answer: Positive-sense single-stranded RNA
Poliovirus is a positive-sense RNA virus, meaning its genomic RNA can act directly as mRNA once it enters the cytoplasm. This allows for the immediate translation of viral proteins by host ribosomes.
Koplik spots are a characteristic early clinical sign of which viral disease?
- A Rubella
- B Measles
- C Mumps
- D Chickenpox
Correct answer: Measles
Koplik spots are small, white lesions on the buccal mucosa that appear before the generalized maculopapular rash. They are considered diagnostic for Measles, a Morbillivirus infection.
Which of the following RNA viruses is associated with the development of adult T-cell leukemia/lymphoma (ATL)?
- A HIV-1
- B HTLV-1
- C Hepatitis C
- D HTLV-2
Correct answer: HTLV-1
HTLV-1 (Human T-lymphotropic virus type 1) is a retrovirus that infects CD4+ T cells. Long-term infection can lead to the malignant transformation of these cells, resulting in ATL. HTLV-2, while closely related, is not associated with ATL.
What is the primary mode of transmission for the Hantavirus (Sin Nombre virus)?
- A Bite of an infected mosquito
- B Inhalation of rodent excreta
- C Sexual contact
- D Consumption of undercooked pork
Correct answer: Inhalation of rodent excreta
Hantaviruses are carried by rodents like the deer mouse. Humans are infected by breathing in dust contaminated with the urine, droppings, or saliva of infected rodents, often leading to Hantavirus Pulmonary Syndrome (HPS).
Which of the following viruses causes 'Hand-Foot-and-Mouth Disease'?
- A Coxsackievirus A16
- B Herpes Simplex Virus 1
- C Variola Virus
- D Human Papillomavirus
Correct answer: Coxsackievirus A16
Coxsackievirus A16 and Enterovirus 71 are the most common causes of this syndrome. It is characterized by fever and vesicular eruptions on the palms, soles, and inside the mouth.
Lassa fever and Ebola virus disease are both viral hemorrhagic fevers, but Ebola belongs to which virus family?
- A Arenaviridae
- B Togaviridae
- C Flaviviridae
- D Filoviridae
Correct answer: Filoviridae
Ebola and Marburg viruses are members of the Filoviridae family, characterized by their long, filament-like structures. Lassa virus belongs to the Arenaviridae family.
Respiratory Syncytial Virus (RSV) is the most common cause of bronchiolitis in infants. It belongs to which family?
- A Orthomyxoviridae
- B Paramyxoviridae
- C Pneumoviridae
- D Coronaviridae
Correct answer: Pneumoviridae
RSV was previously classified under Paramyxoviridae but is now placed in the Pneumoviridae family. It causes fusion of infected cells into large multinucleated syncytia.
The genome of which virus is described as 'ambisense', meaning it contains both positive and negative polarity on the same strand?
- A Influenza virus
- B Rhinovirus
- C HIV
- D Lassa virus
Correct answer: Lassa virus
Arenaviruses like Lassa virus have a bisegmented RNA genome where parts of the RNA segments are negative-sense and other parts are positive-sense. This requires a complex transcription strategy.
Which characteristic differentiates Rubella (German Measles) from Rubeola (Measles)?
- A Rubella is a DNA virus
- B Rubella does not have an envelope
- C Rubella belongs to the Paramyxoviridae family
- D Rubella is teratogenic in early pregnancy
Correct answer: Rubella is teratogenic in early pregnancy
Rubella is a member of the Matonaviridae (formerly Togaviridae) family. While the childhood illness is mild, it is highly teratogenic, causing Congenital Rubella Syndrome (CRS) including deafness, cataracts, and heart defects.
Which RNA virus is known to cause outbreaks of 'Winter Vomiting Disease' on cruise ships and in schools?
- A Rotavirus
- B Sapovirus
- C Astrovirus
- D Norovirus
Correct answer: Norovirus
Norovirus (Caliciviridae) is highly contagious and resistant to many common disinfectants. It spreads rapidly in closed environments through contaminated food, water, and surfaces.