Blood agar plates are an example of which type of microbiological medium?

• A. Selective medium
• B. Enrichment medium
• C. Minimal medium
• D. Differential medium

Answer: (D)

Verified step by step guidance

1. Understand the definitions of each type of microbiological medium: Selective media inhibit the growth of certain microbes while allowing others to grow; Enrichment media enhance the growth of particular microbes by providing specific nutrients; Minimal media contain only the essential nutrients for growth; Differential media allow the differentiation of microorganisms based on their biological characteristics.
2. Recall that blood agar plates contain red blood cells and are used to observe hemolysis patterns, which help differentiate bacterial species based on their ability to lyse red blood cells.
3. Recognize that blood agar does not inhibit the growth of any bacteria (so it is not selective) and it is not minimal since it contains rich nutrients, nor is it specifically designed to enrich certain bacteria over others.
4. Conclude that because blood agar allows differentiation of bacteria by hemolysis (alpha, beta, gamma), it is classified as a differential medium.
5. Summarize that blood agar plates are an example of a differential medium because they help distinguish bacteria based on their hemolytic properties.