Logical reasoning PrepTest 139 · Section 4 · Question 23

Incorrect. If anything, this weakens the argument by suggesting that the genetic changes would bring weed traits to domestic plants, and thus pesticide resistance is unlikely to go from the domestic plants to their weedy relatives. In other words, this answer brings up a reversal.

Incorrect. This answer may strengthen the relationship between the domesticated radishes and the flower color change in their wild relatives, but it doesn't strengthen the argument that this will similarly happen with other traits, or in other plants.

Incorrect. This answer addresses that second comparison that we said was also a sampling flaw by calling the sample into question, thus weakening the argument.

Incorrect. How the domesticated plants ended up with their current coloration is out of scope. What matters is how that trait was then spread through the wild population. If this answer talked about an alternative means that the wild plants ended up with matching coloration—it wasn't genetic drift from the domestic plants, but rather more meddling by the scientists—and ruled it out, then it might serve to strengthen the argument.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen

Stimulus Summary:
Experiment - Domesticated radishes were planted in a field with wild ones (weeds)
Outcome - The wild radishes developed domesticated radish flower colors
Conclusion - Pesticide resistance would also be transferred from domesticated plants to weeds

Answer Anticipation:
This argument treats two different things as similar without establishing them as similar.

The first is the traits that the stimulus discusses. The experiment showed that flower color was passed from domesticated radishes to the wild ones (weeds). From that, it concludes that another trait would similarly be passed along. Since it's relying on these traits being similar, any answer choice that brings up a similarity in these traits as far as the ease with which they're passed from one type of plant to another will strengthen the argument.

The second is the jump from premises about one specific type of plant—radishes—to a more general conclusion about all domesticated crops to related weeds. If domesticated radishes transfer traits more easily to their weedy relatives, then the conclusion would be questionable. (If you viewed this through the lens of a sampling flaw, and you thought about that because there was a study done, that's A+ work!)

Answer Explanation:
This answer is interesting. It brings up a difference between the relevant traits, but it does so in a way that strengthens the argument. How? Well, we wanted the argument to bring up a similarity between the ease with which the flower color trait and the pesticide resistance trait were spread between radishes. This answer actually does that—pesticide resistance is transferred at least as easily as flower color. The answer just goes further and establishes that it's even easier for that trait to be passed along.

Key Takeaway:
Strengthen questions frequently deal with comparative logic. When that happens, arguments that rely on similarities will generally have answers that bring up more relevant similarities. Generally. Be careful with answers that seem to establish a difference but, in doing so, establish that the relevant similarity is present.