#23 - Must Be True

[Jay Donnell]

Hi ataraxia!

You're correct to reason that E brings much more to the table than A, which makes it a less attractive answer in this MBT question.

Pesticide X works essentially in the opposite manner as parathion, which was frankly a terribly counter-productive pesticide. Pesticide X only affects cyclamen mites (the bad guys), whereas parathion only killed the Typhlodromus (the good guys).

In this scenario where they use pesticide X rather than parathion, it seems to essentially control the cyclamen mite population effectively, which is what we know also happens when the Typhlodromus mites are given free rein to do their thing. So, whether the plots have been treated with pesticide X or not, through that pesticide or the normal functioning of Typhlodromus, either way the cyclamen mite population would be effectively controlled.

The whole concept in E about reaching damaging levels more slowly but remaining there longer is unsupported in the passage and the information given in this question itself, so it remains something we are unable to support, nonetheless prove.

Hope that helps!

[kavyakarthic]

Hello,

Why is C incorrect? In the passage, it's clear that if the prey's reproductive rates slow down, the predator's reproductive rate would also slow down. Is the "loss of reproductive synchrony" different than what I just described?


I understand why A is correct, but I'm having trouble understanding why C is incorrect.

[Rachael Wilkenfeld]

We don't know that answer choice (C) would be true. The reproductive synchronicity between the mites could be controlled by the amount of food available for the predator, meaning that if the reproductive rate of the prey mite decreased (decreasing the amount of prey available) the reproductive rate of the predator could also decrease. The synchronicity could be maintained. We aren't able to conclude answer choice (C) for certain, so it's incorrect.

Hope that helps!

[boondoggle]

Hi,

I'm wondering why the forum has this marked as a Must Be True question, since the stimulus is a "most likely"? Am I missing something? To me, (A) is definitely not a Must Be True answer, as we could come up with all sorts of hypothetical reasons as to why the cyclamen mites wouldn't be controlled in the new treated plot.

Thanks!

[Jeff Wren]

Hi boondoggle,

We generally group "Most Strongly Supported" questions under the "Must Be True" question type as they are essentially done the same way, even if the level of certainty for the answers is not 100% for these as it is for "true" Must Be True questions. For each of these, you are asked to use the information in the passage (or the stimulus for Logical Reasoning questions) and only that information to support your answer.

For example, question 27 in this passage is also labeled as "Must be True" although it technically is a "Most Strongly Supported" question. (The question even uses the words "most strongly supports.")

The discussion of "Most Strongly Supported" questions as a variation of "Must Be True" questions can be found in "The Logical Reasoning Bible" in the Must Be True question chapter.

The question does state that pesticide X has "no other direct effect on cyclamen mites or Typhlodromus" (other than slowing the reproduction rate of cyclamen mites), so for the purposes of the hypothetical, you are expected to keep everything else in the experiment constant other than the stated change to the experiment. In other words, while it may be possible that pesticide X could have indirect effects, we're to look for the answer that is most likely based on what we know from the passage without considering possible unknown indirect effects.