Which of the following is not an example of a microbe?

What do photosynthetic microorganisms produce?

The phenomenon that led to the discovery of penicillin involves:

$S$ (Assertion): Alexander Fleming established the full potential of penicillin as an effective antibiotic.
$R$ (Reason): Alexander Fleming discovered penicillin.

Antibiotics are mostly obtained from

Antibiotics are primarily obtained from which of the following sources?