Question

Why are mice killed by smooth (S) strains of Streptococcus, but not rough (R) strains?

• A. Rough strains are virulent, and smooth strains are not.
• B. Rough strains have a polysaccharide capsule that makes the mouse immune system recognize and destroy them.
• C. Smooth strains have a polysaccharide capsule, which hides them from the mouse immune system.
• D. Smooth strains grow faster than rough strains.

Answer 1

Answer: (C)

Correct answer is (c) Smooth strains have a polysaccharide capsule, which hides them from the mouse immune system.