Free Viruses MCQs with Answers
247 Viruses MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Viruses are acellular infectious particles made of genetic material enclosed by a protein capsid, sometimes with a lipid envelope. Their replication depends on a host cell and may follow lytic or lysogenic cycles, so viral structure and reproduction differ fundamentally from those of cellular organisms such as bacteria.
Last updated
247 questions · page 9 of 13
- A. Rough endoplasmic reticulum
- B. Golgi complex
- C. Nuclear envelope
- D. All of these
Explanation: The membrane stalk connecting the virion to the host membrane is constricted and severed to release the enveloped particle.
Correct answer: All of these- A. HIV
- B. Poxvirus
- C. Covid-19
- D. HBV
Explanation: Coronavirus disease (COVID-19) is an infectious disease caused by the SARS-CoV-2 virus.
Correct answer: Poxvirus- A. Vector
- B. Capsid
- C. Plasmid
- D. Genome
Explanation: Viral capsids are the protein cage derived from the protein shell of a virus and can have different shapes, sizes, and protein subunits…
Correct answer: Capsid- A. DNA polymerase
- B. RNA polymerase
- C. Cell enzymes
- D. Viral proteins
Explanation: "DNA polymerase" is the enzyme responsible for converting the single-stranded DNA (ssDNA) virus genome into double-stranded DNA (dsDNA) in…
Correct answer: DNA polymerase- A. Take over the host machinery
- B. Synthesize nucleic acids
- C. To remove the coat of the virus
- D. Both A and B
Explanation: The main purpose of the early viral genes that are expressed is to take over the host machinery and synthesize nucleic acids.
Correct answer: Both A and B- A. Pentagon
- B. Cube
- C. Icosahedron
- D. Pyramid
Explanation: Polyhedral viruses consist of nucleic acid surrounded by a polyhedral (many-sided) shell or capsid, usually in the form of an…
Correct answer: Icosahedron- A. Lytic phage
- B. Lysogenic phage
- C. Prophage
- D. Bacteriophage
Explanation: With lytic phages, bacterial cells are broken open (lysed) and destroyed after immediate replication of the virion.
Correct answer: Lytic phage- A. Louis Pasteur
- B. Edward Jenner
- C. Charles Chamberland
- D. None of the above
Explanation: Charles Chamberland discovered that bacteria cannot pass through porcelain filters.
Correct answer: Charles Chamberland- A. TMV
- B. Smallpox
- C. Poliovirus
- D. Adenovirus
Explanation: Tobacco mosaic virus was the first virus to be crystallized. It was achieved by Wendell Meredith Stanley in 1935.
Correct answer: TMV- A. Penicillin
- B. Streptomycin
- C. Both A and B
- D. None
Explanation: Antibiotics are not effective against viral infections like colds, influenza (flu), most sore throats, bronchitis, and many sinus and ear…
Correct answer: Both A and B- A. Satellite virus
- B. HAV
- C. HCV
- D. HIV
Explanation: Option A is correct as a "satellite virus" is a subviral agent that depends on the co-infection of a host cell with a helper virus for its…
Correct answer: Satellite virus- A. For naked virions, the surface capsid proteins are responsible for binding to a specific cell receptor
- B. For enveloped viruses, the spikes are responsible for binding to a specific cell receptor
- C. Cell lacking a receptor for a specific virus is not infected by that virus
- D. None of the above
Explanation: The virus attachment protein is the viral protein that facilitates the docking of the virus to the plasma membrane of the host cell, the…
Correct answer: None of the above- A. Virophage
- B. Lysophage
- C. Bacteriophage
- D. None of these
Explanation: A bacteriophage is a type of virus that infects bacteria. In fact, the word "bacteriophage" literally means "bacteria eater," because…
Correct answer: Bacteriophage- A. Satellite virus
- B. HAV
- C. HCV
- D. HIV
Explanation: Satellite viruses are a polyphyletic group of viruses encoding structural components of their virions, but incapable of completing the…
Correct answer: Satellite virus- A. Adenovirus
- B. Herpes virus
- C. Poliovirus
- D. None of these
Explanation: The correct option is B as out of all the above-mentioned viruses, only herpes virus is an enveloped virus as it has a lipid envelope…
Correct answer: Herpes virus- A. 1
- B. 20
- C. 3
- D. 4
Explanation: In icosahedral viruses, the capsomeres are arranged in equilateral triangles.
Correct answer: 20- A. Picornavirus
- B. Parvoviruses
- C. Herpes virus
- D. Rotavirus
Explanation: Option B is correct since parvoviruses are the smallest icosahedral particles about 18-26 nm in diameter.
Correct answer: Parvoviruses- A. 100 to 160 nm
- B. 20 to 250 nm
- C. 100 nm to 360 nm
- D. Always below than 100 nm
Explanation: The average diameter of viruses is generally considered to be between 20-250 nanometers (nm), although some viruses can be smaller or…
Correct answer: 20 to 250 nm- A. Rod
- B. Spherical
- C. Tadpole
- D. Helical
Explanation: The shape of TMV virus is rod-shaped or filamentous. TMV stands for Tobacco Mosaic Virus, and it is a type of virus that infects plants…
Correct answer: Rod- A. Yes
- B. No
- C. Provided by cell usually
- D. Provided by virus machinery
Explanation: The attachment of a virus to a host cell does not require energy. The process of virus attachment is typically mediated by specific viral…
Correct answer: No