Arrange the following events in the discovery of Penicillin in the order in which they happened:
A. Fleming traced the effect to a chemical produced by the mould and named it Penicillin.
B. While working on Staphylococci bacteria, Fleming observed a mould in an unwashed culture plate around which Staphylococci could not grow.
C. Ernest Chain and Howard Florey established the full potential of Penicillin as an effective antibiotic.
D. Penicillin was extensively used to treat American soldiers wounded in World War II.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → B, A, C, D
Penicillin, the first antibiotic, was a chance discovery. NCERT tells its story in order: the chance observation, the chemical traced and named, the later work that proved its worth, and then its large-scale use.
B – While working on Staphylococci bacteria, Fleming observed a mould in an unwashed culture plate around which Staphylococci could not grow. This is where the story begins.
A – He found that the effect was due to a chemical produced by the mould and named it Penicillin, after the mould Penicillium notatum.
C – Its full potential as an effective antibiotic was established “much later” by Ernest Chain and Howard Florey.
D – Once its value was proved, “this antibiotic” was used extensively to treat American soldiers wounded in World War II.
The correct order is B, A, C, D.
NCERT Extract:
Antibiotics – “… Do you know that Penicillin was the first antibiotic to be discovered, and it was a chance discovery? Alexander Fleming while working on Staphylococci bacteria, once observed a mould growing in one of his unwashed culture plates around which Staphylococci could not grow. He found out that it was due to a chemical produced by the mould and he named it Penicillin after the mould Penicillium notatum. However, its full potential as an effective antibiotic was established much later by Ernest Chain and Howard Florey. This antibiotic was extensively used to treat American soldiers wounded in World War II.”