With reference to antibiotics, consider the following statements: 1. They are medicines produced from microorganisms that kill or stop the growth of disease-causing microbes. 2. Penicillin was the first antibiotic discovered from a bacterial culture of E. coli. 3. Antibiotics are highly effective against viral diseases like cold and flu. Which of the statements given above is/are correct?

The correct option is (a). Explanation Antibiotics are chemical substances, produced by certain microbes, which function to kill or retard the growth of other disease-causing microbes (pathogens). They are a cornerstone of modern medicine in treating bacterial infections. Statement-wise Analysis: - Statement 1 is Correct: Antibiotics are indeed medicines produced from microorganisms (such as bacteria and fungi) that are used to kill or stop the growth of disease-causing microbes. The term "antibiotic" translates to "against life" (in the context of disease-causing organisms). - Statement 2 is Incorrect: While Penicillin was the first antibiotic to be discovered, it was obtained from a mould (fungus) known as Penicillium notatum, not from a bacterial culture of E. coli. This discovery was made by Alexander Fleming. - Statement 3 is Incorrect: Antibiotics are effective only against bacterial infections. They target specific mechanisms in bacteria, such as cell wall synthesis. Viruses do not possess these mechanisms and live inside host cells; therefore, antibiotics are ineffective against viral diseases like the common cold and flu. Key Takeaway: Antibiotics are antimicrobial drugs derived from microbes (mainly fungi and bacteria) that target bacterial infections; they are ineffective against viral infections, and Penicillin (the first antibiotic) was derived from a fungus.

NCERT Class 8 Science — Chapter 2: Microorganisms : friend and foe

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With reference to antibiotics, consider the following statements:

They are medicines produced from microorganisms that kill or stop the growth of disease-causing microbes.
Penicillin was the first antibiotic discovered from a bacterial culture of E. coli.
Antibiotics are highly effective against viral diseases like cold and flu.

Which of the statements given above is/are correct?

Official previous-year question

Verified 1 Aug 2026.

Options

A1 only
B2 only
C1 and 3 only
D1, 2 and 3

Did you get this right?

Solution

The correct option is (a).

Explanation

Antibiotics are chemical substances, produced by certain microbes, which function to kill or retard the growth of other disease-causing microbes (pathogens). They are a cornerstone of modern medicine in treating bacterial infections.

Statement-wise Analysis:

Statement 1 is Correct: Antibiotics are indeed medicines produced from microorganisms (such as bacteria and fungi) that are used to kill or stop the growth of disease-causing microbes. The term "antibiotic" translates to "against life" (in the context of disease-causing organisms).
Statement 2 is Incorrect: While Penicillin was the first antibiotic to be discovered, it was obtained from a mould (fungus) known as Penicillium notatum, not from a bacterial culture of E. coli. This discovery was made by Alexander Fleming.
Statement 3 is Incorrect: Antibiotics are effective only against bacterial infections. They target specific mechanisms in bacteria, such as cell wall synthesis. Viruses do not possess these mechanisms and live inside host cells; therefore, antibiotics are ineffective against viral diseases like the common cold and flu.

Key Takeaway:

Antibiotics are antimicrobial drugs derived from microbes (mainly fungi and bacteria) that target bacterial infections; they are ineffective against viral infections, and Penicillin (the first antibiotic) was derived from a fungus.

Your note

More from Chapter 2: Microorganisms : friend and foe

With reference to microorganisms, consider the following statements: 1. They are classified into four major groups: bacteria, fungi, protozoa, and algae. 2. They can survive only in moderate climates and die in ice-cold or hot spring environments. 3. Some microorganisms are unicellular, while others are multicellular. Which of the statements given above is/are correct?

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Which one of the following characteristics distinguishes viruses from other microorganisms?

easy

Consider the following statements regarding the habitat of microorganisms: 1. They are found in air, water, and soil but not inside the bodies of animals. 2. They can exist freely as well as grow on other organisms. 3. They are capable of surviving in deserts and marshy lands. Which of the statements given above is/are correct?

medium

Which one of the following human diseases is caused by a protozoan pathogen?

easy

Consider the following pairs of microorganisms and their classification: 1. Aspergillus : Algae 2. Paramecium : Protozoa 3. Penicillium : Fungi 4. Spirogyra : Bacteria How many of the above pairs are correctly matched?

hard

Keep practising Chapter 2: Microorganisms : friend and foe

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The correct option is (a).

Explanation

Statement-wise Analysis:

Statement 1 is Correct: Antibiotics are indeed medicines produced from microorganisms (such as bacteria and fungi) that are used to kill or stop the growth of disease-causing microbes. The term "antibiotic" translates to "against life" (in the context of disease-causing organisms).
Statement 2 is Incorrect: While Penicillin was the first antibiotic to be discovered, it was obtained from a mould (fungus) known as Penicillium notatum, not from a bacterial culture of E. coli. This discovery was made by Alexander Fleming.
Statement 3 is Incorrect: Antibiotics are effective only against bacterial infections. They target specific mechanisms in bacteria, such as cell wall synthesis. Viruses do not possess these mechanisms and live inside host cells; therefore, antibiotics are ineffective against viral diseases like the common cold and flu.

Key Takeaway: