Question

Blood agar is an example of which type of medium?

• A. Enriched media
• B. Indicator media
• C. Enrichment media
• D. Selective media

Hint:

Adding blood as an extra nutrient to a basal agar defines this category.

Answer 1

The Correct Option is A

Step 1: The way to answer is to recall the categories of bacteriological media and what blood contributes. Adding a rich nutrient like blood to a basal agar defines an enriched medium meant for hard-to-grow species.

Step 2: Blood agar is built by mixing 5 to 10 percent defibrinated blood into nutrient agar, giving fastidious bacteria the growth factors they need. That places it squarely in the enriched category, so (a) is the right label.

Step 3: Each wrong option describes a different design. Indicator media use a colour-changing dye to flag a reaction, enrichment broths chemically boost one target organism while holding back the rest, and selective media carry inhibitors to block unwanted flora. None of these describes the action of blood agar.

Step 4: Although blood agar usefully shows haemolysis types and so has a differential role, by definition it is first and foremost an enriched medium.

\[\boxed{\text{Enriched media}}\]