Logical reasoning PrepTest 148 · Section 3 · Question 23

Correct. Argument or Facts:
Facts

Question Type:
Strengthen

Stimulus Summary:
Hypothesis: Antibiotic molecules P serve as molecular pipelines that carry nutrients to internal bacteria.

Answer Anticipation:
Note here that we're not given an argument—instead, we're given a hypothesis to strengthen. As such, we should treat the hypothesis as a conclusion, and look for a scenario in the answer choices (potentially the results of an experiment) that support the hypothesis.

The hypothesis here is that this molecule P (don't get bogged down in trying to pronounce or remember the name, but do note if any answer choice talks about a different molecule) creates channels that lets nutrients get to the bacteria in the interior of a colony. In other words, it solves a problem that bacteria have—colonies need to get food to the middle, and P provides channels for that food to get there. Correct answers will have to deal with this problem/solution dynamic.

Answer Explanation:
This answer provides information about bacterial colonies that don't produce P, which means that, if the hypothesis is correct, they don't have channels to get nutrients to the bacteria in the middle. This answer choice suggests that these bacteria use a different solution—wrinkling their surfaces, which gets more bacteria in contact with the environment where the nutrients are. By showing that bacteria without P have to find an alternative means of solving a problem that P hypothetically solves, this answer strengthens the argument that P solves the problem for the bacteria that have it.

Key Takeaway:
This is a very difficult question, but framing it through a problem/solution lens can help us to recognize that (A) provides an alternative solution to the hypothesized one that's present when the hypothetical solution isn't present. In doing so, it strengthens the argument by showing that bacteria generally need to solve this issue, and they turn to another means when the hypothesized one isn't available.

This is a pretty limited takeaway, but the wider point remains—framing questions in a problem/solution lens can help us understand it and the correct answer better. Even if you didn't see how (A) strengthened the argument, it's the only one that could be framed in that same lens, making it more likely to be correct.

Incorrect. This answer has more to do with the established role of P (fending off other bacteria), so it doesn't impact the hypothesis of another role unrelated to defense.

Incorrect. If anything, this answer suggests that P isn't related to growth, which is inherently related to nutrition. This pushes against the hypothesis.

Incorrect. This answer is about the established role of P, not the hypothesized one, so it's out of scope of what the question is asking.

Incorrect. While this answer doesn't destroy the argument (even if nutrient pipelines are formed, there could still be less nutrients for interior bacteria), it certainly doesn't help it by stating that P does not completely solve the problem. This answer really doesn't provide enough evidence to have much of an impact at all but, if anything, it's against the hypothesis.