Question

The antibiotics have no effect on viruses because
A. Viruses show metabolism of their own
B. Viruses are too small in size for antibiotics to act upon them
C. Viruses show no metabolism of their own
D. Viruses produce a thick covering and encyst themselves as endospore

Answer 1

Viruses are unicellular, ultramicroscopic particles which contain only one type of nucleic acid, either RNA or DNA. They do not possess a cellular organization. They infect nearly all types of living species from small bacteria, microorganisms, to plants, animals. The first virus to be discovered was Tobacco mosaic virus and the discoverer was IVANOSKI.

Complete answer:
Option A- Viruses show metabolism of their own
Living organisms show metabolism as their characteristic feature and since viruses are not living organisms, they are unable to metabolize on their own.
Option B- Viruses are too small in size for antibiotics to act upon them
Antibiotics act on the parts like the cell wall, which are absent in viruses. There is no relation in the effectiveness of antibiotics with the size of virus particles.
Option C- Viruses show no metabolism of their own
Since viruses do not have any cellular organization, they lack enzymes which are essential for protein and nucleic acid synthesis. Also, they don’t have cell walls and show no metabolic processes. But when they enter into the host, viruses set up cellular metabolism and start to make a replica of themselves into the host body.
Option D- Viruses produce a thick covering and encyst themselves as endospore
An endospore is a tough, non-reproductive structure that is usually produced by certain bacteria. Since there is no endospore formation in viruses, they cannot encyst themselves.

Thus, the correct option is option C- Viruses show no metabolism of their own.

Note:
Antibiotics are the substances or agents which are obtained from some microorganisms, and are used to treat infections caused by other organisms. Antibiotics act either by killing the infecting organism or by restricting their growth. The first antibiotic discovered was penicillin.