What percentage of hits are of micro-organism and fungi origin?

• A. 6%
• B. 50%
• C. 12%
• D. 25%

Answer: (C)

In screening campaigns, hits come from a mix of sources, and microbe- and fungus-derived compounds are just one part of that mix. While these organisms are famous for producing diverse bioactive molecules, their share of hits in typical screening datasets tends to be in the low tens of percent. About 12% captures that common representation: a meaningful portion from microorganisms and fungi, but not the majority. The other numbers would imply far larger or smaller contributions than is usually observed across broad libraries, where many hits come from other origins such as synthetic libraries or other natural sources. So 12% best matches the expected distribution in many drug-discovery contexts.