Question Detail
Question
What distinguishes a defined medium from an undefined medium?
Correct Answer
Option A is the correct answer.
Detailed Explanation
A defined medium (or synthetic medium) is one in which the exact chemical composition, and thus the precise quantity of each ingredient, is known. Undefined (or complex) media contain components like yeast extract, meat extract, or peptones, which have variable chemical compositions.
Hint
Consider the meaning of 'defined' in a scientific context. What aspect of the medium's composition would be clearly specified?