Question

Chemicals that inhibit the growth of other harmful microbes by affecting their life processes are called
A. Antibodies
B. Antibiotics
C. Vaccines
D. Antigens

Answer 1

Hint: Microbes invade the host and weaken the system which causes infectious diseases like flu and measles. Microbes also contribute to many non–infectious chronic diseases like certain cancer and coronary heart diseases. Disease-causing microbes are termed as pathogens.

Complete Answer:
An antibiotic is a type of antimicrobial material which is active against microorganisms by either killing or inhibiting its growth. When an infection is suspected of being responsible for an illness but the responsible pathogen has not yet been identified, then an empiric therapy is administered. This therapy involves the injection of a broad-spectrum antibiotic based on the patient’s symptoms. When the responsible pathogen is already known or has been identified, definitive therapy is administered which involves the use of narrow-spectrum antibiotics.
Antibiotics are usually taken by mouth. In severe cases, particularly in chronic systemic infections, antibiotics are given intravenously or by injection. The antibiotic treatment selects bacterial strains that are physiologically or genetically capable of surviving high doses of antibiotics. Under certain conditions, it results in the growth of resistant bacteria, while the growth of susceptible bacteria is inhibited. They do so by:
attacking the wall or coating that surrounds the bacteria
interfering with bacterial reproduction
blocking protein production in bacteria

Thus, the chemicals inhibiting the growth of other harmful microbes by influencing their life processes are called (option B) antibiotics.

Note:
Inappropriate antibiotic treatment or its overuse leads to the emergence of antibiotic-resistant bacteria. Self-prescribing antibiotics is an example of misuse. The overuse of antibiotics, like penicillin or erythromycin, have been associated with emerging antibiotic resistance since the 1950s.