Q23 - Scientist: Some colonies of bacteria produce

[mshinners]

Question Type:
Strengthen

Stimulus Breakdown:
Hypothesis: P creates pipelines to interior bacteria so they can eat.

Answer Anticipation:
"Essential" nutrients is a key phrase here, as it denotes that these nutrients are needed by the bacteria. I don't know how that's going to play into the answer, but it seems important because of the extreme language.

We don't really have any premises here; we're trying to support a hypothesis that P does this necessary function. I'm therefore expecting the answer choice to either give evidence that P actually does this (studies; chemistry explaining how it works) or that bacteria without P have to find some other way to carry out this essential function.

Correct answer:
(A)

Answer choice analysis:
(A) It would be easy to eliminate this on the first pass by (incorrectly) thinking that bacteria without P is out of scope. However, since we know P carries out an essential function, we do actually know something about non-P bacteria from the stimulus - they must find another way to do this essential function. This answer choice explains what that is - they get wrinkly so they don't need pipelines - the bacteria directly gets the nutrients.

Compared to (C), this answer is directly tied to the hypothesis. (C) definitely suggests P is related to nutrition, but it doesn't mention how it's related (the argument needs it to form pipelines). (A) definitely gets at the pipelines by suggesting a similar alternative for bacteria that lack P. This answer also connects it to nutrition, though not directly. The hypothesis states the essential nutrients are in the surrounding area, and (A) mentions access to the surrounding area, thus indirectly bringing nutrition into this answer. Since it has all the components of the hypothesis whereas (C) lacks some, this is our answer.

This absolutely would not be a first-round pick. Absolutely not. The important thing for this question is to get this answer to survive your first pass.

(B) Wrong scope. This answer suggests that P is more closely related to its other purported function - fending off other bacteria. That definitely doesn't strengthen a conclusion about using it to eat.

(C) Tempting. Very tempting. This answer choice definitely is in scope since it deals with nutrients. I think this question should have come down to (A) vs. (C)

At that point, looking at the two answers, this one talks about nutrients but not the pipeline; (A) talks about the pipeline (by establishing an alternative) but not nutrients. This would then require looking at the hypothesis to see which is closer.

Checking the hypothesis, it's about P forming pipelines to the surrounding area to give access to nutrients. This answer choice suggests P has something to do with nutrients, but there's no information about how it's related. Since this answer doesn't impact the likelihood that pipelines are formed, we can rule it out.

(D) Similar to (B), this answer choice connects P with fending off other bacteria, so it doesn't support an argument about it being used to eat.

(E) Missing scope. Why are they dying? It could be from lack of food (which would actually suggest that P isn't fully doing its job), but it could also be from other factors (in which case this answer isn't about eating at all, and it's out of scope). Since this answer leaves us with questions, it can't have an impact on the conclusion.

Takeaway/Pattern:


#officialexplanation

[haeeunjee]

(C) was easier for me to eliminate than (E).

"grow as quickly" is so vague --

Well what if when they aren't buried in nutrient-rich soil, bacteria w/o phenazines actually grow quicker than bacteria w/ phenazines? That possibility holds. What if the two types of bacteria ALWAYS grow as quickly as each other, whether in nutrient-rich soil or otherwise? There's too much vagueness, too many questions and ambiguity for this answer choice to be a great strengthener.

[AyakiK696]

So A is correct because it provides a different situation and shows how ants in this group have another means for gaining access to essential nutrients? My only issue with this answer is the fact that it seems that we have to make an assumption in order for it to work, which is that the wrinkled surfaces are used to help the other group gain access to nutrients. Would a Weaken answer to this Q be one that shows how colonies with phenazines actually have alternative means of accessing essential nutrients?

[ohthatpatrick]

Remember that the most common way to strengthen any hypothesis (on LSAT) is to provide examples where

when the supposed CAUSE is absent, the supposed EFFECT is absent
(sorta like a Control Group)

In this case,
a need to feed the interior bacteria causes the effect of phenazine pipelines.

In (A) case,
there is no need to feed the interior bacteria (because there are fewer interior bacteria in a wrinkled surface), and thus there is no need for phenazine pipelines.

And your hypothetical "phenazines are present, but NOT needed to feed interior bacteria" would indeed be a good weaken idea.