Question

Agar is used as culture medium because it.

• A. Provides nourishment
• B. Remains as solid jelly
• C. Resistant to microorganic breakdown
• D. Both B and C

Answer 1

The correct option is D Both B and C

A. Agar is a polysaccharide (polymers of sugar units) which is indigestible by most bacteria and hence it cannot be used as a source of nutrition.

B. Agar, melts at 85 degree Celsius and solidifies upon cooling, thus providing a solid substratum for the bacteria to grow and form colonies.

C. Agar is resistant to bacterial degradation because most bacteria lack the enzyme required for agar utilization.

D. Correct answer.