Explanation:

Antibiotics are chemical substances that are used to treat bacterial infections. Antibiotics can be classified based on their spectrum of activity. The spectrum of activity of an antibiotic refers to the range of microorganisms against which it is effective.

Narrow Spectrum Antibiotics:

Narrow-spectrum antibiotics are effective only against a limited number of microorganisms. They are usually targeted against a specific type of bacteria. These antibiotics are used to treat infections caused by a specific organism or group of organisms. Examples of narrow-spectrum antibiotics include:

- Penicillin G: Effective against only a few types of bacteria like Streptococcus and Neisseria.

- Vancomycin: Effective against only a few types of bacteria like Staphylococcus and Streptococcus.

Broad Spectrum Antibiotics:

Broad-spectrum antibiotics are effective against a wide range of microorganisms. They are usually used to treat infections caused by unknown or multiple types of bacteria. These antibiotics do not distinguish between harmful and beneficial bacteria. Examples of broad-spectrum antibiotics include:

- Tetracycline: Effective against a wide range of bacteria like Mycoplasma, Chlamydia, and Rickettsia.

- Ciprofloxacin: Effective against a wide range of bacteria like Escherichia coli, Salmonella, and Pseudomonas.

Limited Spectrum Antibiotics:

Limited-spectrum antibiotics are effective against a few types of harmful microbes and cells. They are usually used to treat infections caused by a specific organism or group of organisms. Examples of limited-spectrum antibiotics include:

- Nitrofurantoin: Effective against only a few types of bacteria like Escherichia coli and Staphylococcus.

- Metronidazole: Effective against only a few types of bacteria like Helicobacter pylori and Bacteroides.

Conclusion:

The given antibiotic X is effective only against a few types of harmful microbes and cells. Thus, X is a limited spectrum antibiotic.