A Colony of Mice Is Treated with a Nonvirulent Strain

question 60

Multiple Choice

A colony of mice is treated with a nonvirulent strain of the bacterium Streptococcus pneumoniae . Before treatment, a researcher exposed this nonvirulent strain to heat-killed cells of a virulent strain. What will be the effect on the mouse population?

• A) The mice will all remain healthy.
• B) Some mice will develop a paralytic condition, but most will remain healthy.
• C) Most or all of the mice will develop pneumonia.
• D) Some mice will develop pneumonia, but most will remain healthy.
• E) The mice will become immune to the bacteria.