Logical reasoning PrepTest 135 · Section 4 · Question 23

Question prompt

Biologist: Researchers believe that Remaining source text redacted.
Why the credited answer is right

Credited answer: B

The notes below walk through why it fits the stem and how to eliminate the rest.

Argument or Facts

Argument

Valid or Flawed

Flawed

Question Type

Strengthen with Necessary Premise Questions

Stimulus Summary

Dogs are descended from trained wolves. Some dog DNA is closer to wolf DNA than other dog DNA, so those dogs were domesticated more recently.

Answer Anticipation

Don’t get confused by the genetics! This argument is about comparisons and timelines, and how they’re connected. Framing it that way can get us away from the science!
Here, the conclusion is that some dog breeds were domesticated from wolves more recently than other dog breeds. Why? Because their DNA is closer/more similar to wolf DNA. So the argument here is connecting the closeness of DNA to the timeline of one breed being domesticated to another. Something like:
If one descendant breed’s DNA is closer to a parent species than another descendant breed’s, then the more similar breed was domesticated more recently than the less similar one.

Answer choices

  1. A
    If one breed of Remaining source text redacted.
    Why choice A is not credited
    Two issues here. First, it talks about the wolves “from which most other breeds” were domesticated, and there’s no similar lumping of most breeds to a single group of wolves. Second, this answer establishes something that “may” be true, which is less certain than the argument’s conclusion.
  2. B
    If one breed of Remaining source text redacted.
    Why choice B matches the stem
    This answer connects the closeness of the relationship to the timeline of the breed being domesticated, so it’s the correct answer.
  3. C
    Any breed of dog Remaining source text redacted.
    Why choice C is not credited
    This answer has nothing to do with the timeline of domestication, so it can’t serve as a principle justifying a conclusion about that timeline.
  4. D
    If one breed of Remaining source text redacted.
    Why choice D is not credited
    This answer has nothing to do with the timeline of domestication, so it can’t serve as a principle justifying a conclusion about that timeline (two answer choices for one reason!).
  5. E
    Any two breeds of Remaining source text redacted.
    Why choice E is not credited
    The conclusion is about different timelines for domestication for different breeds, so an answer that talks about two breeds both being domesticated “long ago” doesn’t help to create the spectrum of a timeline we need for the varying domestication.

What this tests

Question analytics

Based on historical answer selection rates for this question.

Answer choice distribution

  1. A 30%
  2. B Credited 48%
  3. C 4%
  4. D 14%
  5. E 3%

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