Question

Antibiotics are produced by
A. Bacteria
B. Bacteriophages
C. Protozoan
D. Plants

Answer 1

They are the type of biological cells that constitute a large number of prokaryotic microorganisms. These are the unicellular organisms that can live in soil. The membrane bound cell organelles or nucleus are absent.

Complete step by step answer:
Antibiotics are the substances that can inhibit or destroy the growth of bacteria or other microorganisms. They are used to treat bacterial infections and can be produced in the environment by fungi and soil bacteria.
Antibiotics prevent the bacterial cells from multiplying and because of this population bacteria remains the same. This allows the host’s defence mechanism to fight or kill the bacterial infection. Gramicidin is the first antibiotic that was manufactured commercially. The heterogenous mixture of six compounds and these antibiotic compounds obtain from the soil bacteria species i.e. Bacillus brevis.
The largest antibiotic producing genus is the Streptomyces that produces anti-fungal, anti-parasitic and anti-bacterial drugs.

Thus, the correct answer is option (A).

Additional information:
Penicillin drugs are the antibiotics that are produced by the molds and these are the first successfully treated antibiotics for the treatment of many serious infections. But most of the natural antibiotics are synthesized by bacteria.

Note:
Antibiotics are produced by bacteria. Bacteria is a unicellular-microorganism that lacks nucleus and other membrane bound cell organelles. Streptomyces, penicillin and gramicidin are some antibiotics that are used to treat serious diseases.