All Free Biology MCQs with Answers

2711. Which process/es take/s place during the lytic cycle?

• A. Replication
• B. Transcription
• C. Translation
• D. All of these

Explanation: The correct answer is D) All of these, as replication, transcription, and translation all take place during the lytic cycle of viral infection.

2712. Pick the false statement about AIDS:

• A. HIV infection
• B. Reverse transcription in HIV particle
• C. Destruction of T cells
• D. Cure after proper medication

Explanation: The false statement is D) Cure after proper medication, as there is currently no cure for HIV/AIDS. While antiretroviral therapy (ART) can control the infection, it does not provide a cure.

2713. Virus attacks and hijacks host's _.

• A. Mitochondria
• B. Nucleus
• C. Ribosomes
• D. Endoplasmic reticulum

Explanation: The correct answer is C) Ribosomes, as many viruses hijack the host cell's ribosomes to produce viral proteins required for the replication and assembly of new viral particles.

2714. It is anti-viral:

• A. Penicillin
• B. Streptomycin
• C. Tetracycline
• D. Interferon

Explanation: The correct answer is D) Interferon, as it is an antiviral protein produced by the body's immune system to combat viral infections.

2715. _ is the second major form of hepatitis.

• A. Hapatitis A
• B. Hepatitis B
• C. Hepatitis C
• D. Hepatitis D

Explanation: The correct answer is B) Hepatitis B, as it is the second major form of hepatitis caused by the Hepatitis B virus (HBV).

2716. Which structure is involved in the transfer of genetic material from one bacterium to another?

• A. Flagella
• B. Pilli
• C. Cytoplasm
• D. Mesosomes

Explanation: The correct answer is B) Pili, as they are the structures involved in the transfer of genetic material from one bacterium to another during conjugation.

2717. Salmonella typhi exhibits which shape?

• A. Spherical
• B. Spiral
• C. Rod-shape
• D. Comma-shape

Explanation: The correct answer is C) Rod-shape, as Salmonella typhi exhibits a rod-shaped morphology.

2718. All of the following bacteria have definite shapes except:

• A. Clostridium tetani
• B. Spirillum
• C. Salmonella typhi
• D. Mycoplasma

Explanation: Mycoplasma is a type of bacteria that lacks a rigid cell wall. As a result, it doesn't have a definite shape like other bacteria. This group of bacteria is often referred to as "pleomorphic," meaning they can take on various shapes or sizes, ranging from spherical to filamentous. The absence of a cell wall is a unique feature of Mycoplasma, which distinguishes it from other bacteria.

2719. Antibiotics that kill microbes immediately are called _.

• A. Microbistatic
• B. Biostatic
• C. Microbicidal
• D. Chemotherapeutic

Explanation: Microbicidal accurately describes antibiotics that directly and immediately kill microbes, while the other options refer to different modes of microbial control without immediate killing.

2720. Mesosomes are infoldings of the cell membrane and are involved in:

• A. DNA replication
• B. Protein synthesis
• C. RNA synthesis
• D. Metabolism

Explanation: Mesosomes are the areas in the cell membrane of prokaryotic cell which fold inwards. It helps in cell wall formation, DNA replication, respiration and increases the surface area of the plasma membrane.