All Free Biology MCQs with Answers

• A. HSV-2
• B. Varicella-zosster virus
• C. Oncovirus
• D. Picornavirus

Explanation: An oncovirus or oncogenic virus is a virus that can cause cancer. Hence, C is the correct option.

• A. 250
• B. 200
• C. 150
• D. 100

Explanation: Option B is correct as there is are 200 bacteriophages produced after 25 minutes of initial infection.

• A. The mitochondrion of the cell
• B. Cell membrane of host cell
• C. Endoplasmic reticulum of the cell
• D. None of these

Explanation: Correct option is B. The outermost layer of a virus is the envelope. A large number of viruses do not have envelopes.

• A. Lytic phage
• B. Lysogenic phage
• C. Prophage
• D. Bacteriophage

Explanation: Option A : The phage which causes lysis of host cells is known as lytic or virulent phage.

• A. Self replication in host cell
• B. Duplication
• C. Self duplication
• D. Multiplication in host cell

Explanation: Option: A Bacteriophages have been widely used in genetic research because they can easily replicate inside host cells.

• A. Bacteria
• B. Viruses
• C. Fungi
• D. Both A and B

Explanation: According to Ivanovski, the term "soluble living germs" refers to the infectious agent responsible for causing the disease tobacco mosaic…

• A. Injecting DNA
• B. Replication
• C. Dissolve bacterial cell wall
• D. All of these

Explanation: The lysozyme enzyme is a digestive enzyme that 'digests the bacterial cell wall'.

• A. HIV
• B. Poxviruses
• C. Covid-19
• D. HBV

Explanation: The poxviruses are the largest known DNA viruses and are distinguished from other viruses by their ability to replicate entirely in the…

• A. Virulent phage
• B. Lytic phage
• C. Temperate phage
• D. Both A and B

Explanation: The correct statement is that the phage causing the lysogenic cycle is a "Temperate Phage." Temperate phages can enter the lysogenic…

• 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.

• 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.

• 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…

• 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…

• 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.

• 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…

• 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.

• 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.

• 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.

• 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…

• 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…