If the bacterium Staphylococcus aureus experiences a cost for maintaining one or more antibiotic-resistance genes, then what should happen in environments from which antibiotics are missing?
A) These genes should continue to be maintained in case the antibiotics ever appear.
B) These bacteria should be outcompeted and replaced by bacteria that have lost these genes.
C) The bacteria should try to make the cost worthwhile by locating, and migrating to, microenvironments where traces of antibiotics are present.
D) The bacteria should start making and secreting their own antibiotics.

Question

Quizplus · Accepted Answer

When antibiotics are missing, there is no selection pressure for maintaining antibiotic resistance genes, meaning that the cost of maintenance becomes a burden. In such an environment, bacteria that have lost these genes will have a competitive advantage over those that still carry them, leading to their replacement over time.

If the Bacterium Staphylococcus Aureus Experiences a Cost for Maintaining