Question

Viruses which kill bacteria are known as

• A. Virion
• B. Viriods
• C. Bacteriophages
• D. Antibodies

Hint:

The term "Bacteriophage" was coined by Félix d'Hérelle in 1917.
Phages are highly host-specific, which makes them valuable tools in phage therapy to treat bacterial infections, especially in the era of antibiotic resistance.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Viruses are obligate intracellular parasites that require a host organism to replicate.
They can target different types of host organisms, including plants, animals, fungi, and bacteria.

Step 2: Detailed Explanation:
Viruses that specifically infect, replicate within, and ultimately destroy bacterial cells are called bacteriophages (literally meaning "bacteria eaters").
A bacteriophage typically consists of an outer protein capsid enclosing genomic material, which can be either DNA or RNA.
The infection cycle begins when the bacteriophage attaches to specific surface receptors on the bacterial host cell wall.
It injects its genetic material into the bacterium, hijacking the host's metabolic machinery to synthesize viral proteins and replicate genomic DNA.
Once new phage particles are assembled inside the bacterium, they produce lytic enzymes (such as endolysins) that break down the bacterial cell wall, causing cell lysis and death, and releasing progeny phages.
In contrast, a "virion" is a complete, infective viral particle outside a host cell.
"Viroids" are smaller, infectious agents consisting solely of short, naked, single-stranded circular RNA without a protein coat, primarily causing plant diseases.
"Antibodies" are protective proteins produced by animal immune systems to neutralize pathogens and are not viruses.

Step 3: Final Answer:
Viruses that infect and kill bacteria are known as bacteriophages.