Manhattan CAT 4 Question 22

[JbhB682]

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.

Which of the following can be inferred about antibiotic-resistant bacteria?
a) If bacteria did not contain antibiotic-resistant plasmids, then they would be incapable of developing resistance to antibiotics.
b) Human involvement is necessary in order for bacteria to develop resistance to antibiotics.
c) The United States should ban the use of antibiotics for non-therapeutic uses.
d) If bacteria were not able to adapt quickly to new environments, it would be more difficult for bacteria to develop resistance to antibiotics.
e) Critically ill patients with infections due to antibiotic-resistant bacteria are more likely to die.

Question :

1) my understanding is inference questions general involve "localizing" or "finding information in the passage" based on the information in the question stem

however this question is so generic in regards to where to look .. seems like i need to infer from any line in this passage

A) should i be basing my answer on my notes or should i re-read the entire passage ?

whats the best strategy

Question 2

I eliminated D because i could not understand what it was saying ....is this a fair way to re-word D

If bacteria cant adapt quickly, it would get tougher for them to develop resistance

[Sage Pearce-Higgins]

One of the reasons that this question is in the 700-800 range is that information relevant to the answer could be found anywhere in the passage, making it time-consuming. You need to pick out the relevant information in the passage (I don't see how your notes could help you here), but you also need to apply the vital question to each answer choice "Does this have to be true?"

What will help you here is to notice some of the clues in the answer choices: 'would be incapable' is a strong claim, suspicious for an inference answer; 'is necessary' likewise; 'should ban' is a value judgement, and there are no value judgments in the passage; 'are more likely to die' is, again, a strong claim, as well as a poor comparison (more likely to die than who?). These are clues, not certain logic, but they can help to speed things up.

The crucial sentence for answer D is 'because bacteria adapt quickly to new environmental conditions, many bacteria harmful to humans have developed ways to circumvent the effects of antibiotics'. If I just flip the wording, then it gives me answer D. Take the following example:

Because I'm wearing a think coat, I don't feel cold.
From this I can correctly infer that:
If I wasn't wearing a thick coat, I would feel cold.