More than half of our antibiotics are derived from which of the following sources?

• A. Plant extracts
• B. Minerals from the Earth's crust
• C. Microorganisms such as bacteria and fungi
• D. Synthetic chemical processes

Answer: (C)

Verified step by step guidance

1. Understand that antibiotics are substances used to kill or inhibit the growth of bacteria and other microorganisms.
2. Recall the historical origin of most antibiotics, which were discovered by studying natural sources.
3. Recognize that many antibiotics come from microorganisms, especially bacteria and fungi, because these organisms produce compounds to compete with other microbes in their environment.
4. Eliminate options that are less common sources of antibiotics, such as plant extracts, minerals, or purely synthetic chemicals.
5. Conclude that the majority of antibiotics are derived from microorganisms such as bacteria and fungi, which have been the primary natural source for antibiotic discovery.