Antibiotics are chemical substances that kill or inhibit the growth of bacteria. The success of antibiotics against disease-causing bacteria is one of modern medicine's great achievements. However, because bacteria adapt quickly to new environmental conditions, many bacteria harmful to humans have developed ways to circumvent the effects of antibiotics, and many infectious diseases are now much more difficult to treat than they were just a few decades ago. Critically ill patients are more likely to require the aid of antibiotics to fight infections, so are more likely to be harmed by the spread of antibiotic-resistant bacteria.
Bacteria contain genetic material called plasmids, which can carry the genes enabling antibiotic resistance. Bacteria share these plasmids among one another via a direct, mechanical transfer between cells, and antibiotic-resistant plasmids can thus spread easily throughout a bacterial population to create a strain of resistant bacteria. Less commonly, a natural chromosomal mutation may confer antibiotic resistance on a bacterium, which can then reproduce and become dominant via natural selection, likely when that colony is exposed to antibiotics. In the absence of human involvement, however, bacteria rarely develop resistance to antibiotics.
On January 1, 2006, the European Union banned the feeding of all antibiotics to livestock for non-therapeutic purposes. This sweeping policy followed a 1998 ban on the non-therapeutic use of four medically-important antibiotics on animals. In the United States, by contrast, animals raised on industrial-scale factory farms are still routinely administered low levels of antibiotics in their feed-not as a cure for ongoing maladies, but primarily as a growth-enhancing agent to produce more meat and also as a prophylactic measure to compensate for overcrowded and unsanitary conditions. Currently, several antibiotics that are used in human medical treatment, such as tetracycline, penicillin and erythromycin, are also administered non-therapeutically to healthy livestock and poultry. This long-term non-therapeutic use of antibiotics in the United States creates the ideal conditions for the development of antibiotic-resistant bacteria, as the drugs kill only the susceptible bacteria, leaving the resistant strains to reproduce and flourish. The newly-resistant bacteria can then spread from farm animals to other animals, including humans.
According to the passage, why are antibiotic-resistant bacteria problematic for humans?
Antibiotics are no longer effective in treating disease.
Some diseases are harder to treat because some antibiotics are less able to fulfill their prescribed function.
Bacteria spread more easily in a hospital setting due to the close proximity of many patients who may harbor different bacteria.
Bacteria can infect both humans and animals.
Bacteria gain resistance via the exchange of plasmids.
Target Test Prep is 20% off right now!
Use code FLASH20
Available with Beat the GMAT members only code
MORE DETAILS
Manhattan RC query
This topic has expert replies
GMAT/MBA Expert
-
ceilidh.erickson
- GMAT Instructor
- Posts: 2095
- Joined: Tue Dec 04, 2012 3:22 pm
- Thanked: 1443 times
- Followed by:247 members
It's helpful if you explain what you thought the answer was, and why you're confused. That helps us to better address your specific concerns.
In this question, the phrase "according to the passage" tells us that we're looking for a specific detail explicitly stated in the passage. The first thing you should do is go back to the passage and see what it says about humans:
When looking through the answer choices, focus on what you can ELIMINATE in wrong answers:
A) Antibiotics are no longer effective in treating disease.
This is too strong. We are told that "many" bacteria can circumvent antibiotics. This doesn't mean that ALL antibiotics are no longer effective.
B) Some diseases are harder to treat because some antibiotics are less able to fulfill their prescribed function.
The word "some" often shows up in right answers, because it's hard to disprove. If critically ill patients need antibiotics, but those sometiems antibiotics are less effective because of resistant bacteria, then those diseases will be harder to treat. Correct.
C) Bacteria spread more easily in a hospital setting due to the close proximity of many patients who may harbor different bacteria.
This one is tricky, because this is probably true... in the real world. The passage doesn't mention anything about hospitals, though, so this answer would not be "according to the passage."
D) Bacteria can infect both humans and animals.
Here again, we have a statement that is true... but it doesn't answer the question. The passage does tell us that bacteria can spread from animals to humans, but this doesn't tell us WHY resistant bacteria are a problem for humans.
E) Bacteria gain resistance via the exchange of plasmids.
Once again, this is true according to the passage. But the fact that they gain resistance via plasmids doesn't tell us anything about WHY they are harmful to humans.
The answer is B.
With SPECIFIC DETAIL questions, wrong answer choices often contain true information. We're tempted to pick them because we think, "yup, I remember reading that." You have to make sure that your answer choice ANSWERS THE RIGHT QUESTION, though.
According to the passage, why are antibiotic-resistant bacteria problematic for humans?
In this question, the phrase "according to the passage" tells us that we're looking for a specific detail explicitly stated in the passage. The first thing you should do is go back to the passage and see what it says about humans:
If harmful bacteria can circumvent antibiotics, but critically ill patient require the help of antibiotics (implying that their own immune systems are not enough to fight the bacteria), then critically ill patients may not be able to fight off the harmful bacteria.... because bacteria adapt quickly to new environmental conditions, many bacteria harmful to humans have developed ways to circumvent the effects of antibiotics, and many infectious diseases are now much more difficult to treat...
...Critically ill patients are more likely to require the aid of antibiotics to fight infections, so are more likely to be harmed by the spread of antibiotic-resistant bacteria...
When looking through the answer choices, focus on what you can ELIMINATE in wrong answers:
A) Antibiotics are no longer effective in treating disease.
This is too strong. We are told that "many" bacteria can circumvent antibiotics. This doesn't mean that ALL antibiotics are no longer effective.
B) Some diseases are harder to treat because some antibiotics are less able to fulfill their prescribed function.
The word "some" often shows up in right answers, because it's hard to disprove. If critically ill patients need antibiotics, but those sometiems antibiotics are less effective because of resistant bacteria, then those diseases will be harder to treat. Correct.
C) Bacteria spread more easily in a hospital setting due to the close proximity of many patients who may harbor different bacteria.
This one is tricky, because this is probably true... in the real world. The passage doesn't mention anything about hospitals, though, so this answer would not be "according to the passage."
D) Bacteria can infect both humans and animals.
Here again, we have a statement that is true... but it doesn't answer the question. The passage does tell us that bacteria can spread from animals to humans, but this doesn't tell us WHY resistant bacteria are a problem for humans.
E) Bacteria gain resistance via the exchange of plasmids.
Once again, this is true according to the passage. But the fact that they gain resistance via plasmids doesn't tell us anything about WHY they are harmful to humans.
The answer is B.
With SPECIFIC DETAIL questions, wrong answer choices often contain true information. We're tempted to pick them because we think, "yup, I remember reading that." You have to make sure that your answer choice ANSWERS THE RIGHT QUESTION, though.
Ceilidh Erickson
EdM in Mind, Brain, and Education
Harvard Graduate School of Education
EdM in Mind, Brain, and Education
Harvard Graduate School of Education
