Which of the following is true of a pure culture in microbiology?

• A. It contains only one species of microorganism.
• B. It cannot be used for studying microbial metabolism.
• C. It is always obtained directly from environmental samples.
• D. It contains multiple species growing together.

Answer: (A)

Verified step by step guidance

1. Understand the definition of a pure culture in microbiology: a pure culture consists of microorganisms that are all descendants of a single cell, meaning they are genetically identical or very similar and belong to the same species.
2. Recognize that a pure culture is essential for studying specific characteristics of a microorganism, such as its metabolism, because it eliminates the influence of other species.
3. Note that pure cultures are typically obtained by isolating a single species from a mixed environmental sample through techniques like streak plating, not directly from the environment without isolation.
4. Recall that a pure culture cannot contain multiple species growing together; if multiple species are present, it is considered a mixed culture.
5. Conclude that the statement 'It contains only one species of microorganism' correctly describes a pure culture.