Question

An antibiotic was effective 20 years ago against a specific type of a specific type of bacterial infection no longer works against the same kind of infection today. Which best explains why the antibiotic is no longer as effective as it was 20 years ago?
a. Bacteria resistant to the antibiotic have killed off nonresistant bacteria
b. have changed the structure of the bacteria that causes the infection
c. Resistant bacteria have survived and reproduced at a greater rate than nonresistant bacteria
d. The human body has developed an immunity to the antibiotics

Answer 1

c. Resistant bacteria have survived and reproduced at a greater rate than nonresistant bacteria

Explanation:

The antibiotic is no longer effective as it was 20 years ago because the resistant bacterial have survived and reproduced at a greater rate than the non-resistant bacteria.

• The antibiotics have specifically designed to exterminate the disease causing bacteria strain from the body.
• While at that point in time, it is potent and does the work. Along the line, it will cause the structures of some other strains to change.
• This will lead to the development of resistant breeds with time.
• The resistant breed will then be able to survive the onslaught of the antibiotics making it not a good fit.

Learn more:

Selective force brainly.com/question/4602376

#learnwithBrainly