Critical Reasoning

Caterpillars of all species produce an identical hormone called "juvenile hormone" that maintains feeding
behavior. Only when a caterpillar has grown to the right size for pupation to take place does a special enzyme
halt the production of juvenile hormone. This enzyme can be synthesized and will, on being ingested by
immature caterpillars, kill them by stopping them from feeding.

Which of the following, if true, most strongly supports the view that it would NOT be advisable to try to eradicate
agricultural pests that go through a caterpillar stage by spraying croplands with the enzyme mentioned above?

(A) Most species of caterpillar are subject to some natural predation.
(B) Many agricultural pests do not go through a caterpillar stage.
(C) Many agriculturally beneficial insects go through a caterpillar stage.
(D) Since caterpillars of different species emerge at different times, several sprayings would be necessary.
(E) Although the enzyme has been synthesized in the laboratory, no large-scale production facilities exist
as yet.

OA is C

Anyone can help explain why E is incorrect? I choose E because if the production facilities do not exist yet, it is undoubtly unwise for the farmers to use this method, because scientists just cannot produce enough such enzyme. Why this cannot weaken those who suggest to spray such enzyme?

Any experts can give some suggestions because I really find myself beaten by critical reasoning. I just don't know how to beat the critical reasoning. Sometimes I find some questions quite easy, but sometimes a certain question may drives me crazy. Sometimes I bang my head to walls again and again, and still cannot understand. Anyone can give me some suggestions? I have study CR for more than half a year and still don't know what the CR wants to test us. To test our IQ? Or to test our ability to find relevant and irrelevant information?

Can any experts say something?????

E is wrong because it addresses whether it is possible to spray the enzyme, not whether is it advisable. This question requires careful reading of the stem.

It isn't unwise to spray - it might be a very good decision; it is simply impossible.

i think its quiet easy to choose C

rx_11 wrote:Caterpillars of all species produce an identical hormone called "juvenile hormone" that maintains feeding
behavior. Only when a caterpillar has grown to the right size for pupation to take place does a special enzyme
halt the production of juvenile hormone. This enzyme can be synthesized and will, on being ingested by
immature caterpillars, kill them by stopping them from feeding.

Which of the following, if true, most strongly supports the view that it would NOT be advisable to try to eradicate
agricultural pests that go through a caterpillar stage by spraying croplands with the enzyme mentioned above?

(A) Most species of caterpillar are subject to some natural predation.
(B) Many agricultural pests do not go through a caterpillar stage.
(C) Many agriculturally beneficial insects go through a caterpillar stage.
(D) Since caterpillars of different species emerge at different times, several sprayings would be necessary.
(E) Although the enzyme has been synthesized in the laboratory, no large-scale production facilities exist
as yet.

OA is C

Anyone can help explain why E is incorrect? I choose E because if the production facilities do not exist yet, it is undoubtly unwise for the farmers to use this method, because scientists just cannot produce enough such enzyme. Why this cannot weaken those who suggest to spray such enzyme?

Any experts can give some suggestions because I really find myself beaten by critical reasoning. I just don't know how to beat the critical reasoning. Sometimes I find some questions quite easy, but sometimes a certain question may drives me crazy. Sometimes I bang my head to walls again and again, and still cannot understand. Anyone can give me some suggestions? I have study CR for more than half a year and still don't know what the CR wants to test us. To test our IQ? Or to test our ability to find relevant and irrelevant information?

Can any experts say something?????

The trick to CR is to predict what the correct answer has to do -- before you look at the answer choices. It's much easier to find the correct answer if you know what you're looking for.

In the CR above, the correct answer has to show why it would be a bad idea to spray the enzyme.

Only answer choice C explains why it would be a bad idea: because the enzyme would kill insects that are agriculturally beneficial.

The other two experts have really covered what is going on here (great points!) so I thought I might address your question about what is being tested with critical reasoning.

IQ? Well I would love to think so, but I have seen students improve dramatically on Critical Reasoning for both the LSAT and the GMAT -- did they suddenly get that much smarter? IQ, whatever it means is a part of everything especially in a time crunch but something else is tested here.

I would say that what is being tested is strategy and proper attention to the proper detail.

Please try this in critical reasoning.

1) Work really hard to get good at identifying the conclusion every time. For Paradox questions and Inference questions the conclusion is not the focus, but for others you must accurately identify the conclusion. Do you do this well? Do you need some help with that?

2) Once you have the conclusion look before and after the conclusion (usually only before the conclusion since the conclusion is at the end of most GMAT problems). There should be one piece of evidence that I call the "Most Important Premise." This evidence is what is really leading to the conclusion. The other evidence is really background information and does not have to be looked at in as much detail.

Those who are good at critical reasoning have their focus on the conclusion and the evidence that directly leads to that conclusion.

Every word of the conclusion has potential meaning...whereas with background information it has only a little meaning taken together. Really look at where you are trying to go in a question - i.e. the conclusion. In this case the conclusion is in the question stem and those words are very important...

Thanks very much experts and friends!!!

I think maybe I find the right way. Strategy and identify proper information. Focus on conclusion and direct premise. Haha, that really helps!!! Thanks!!

Hi All,
I can understand all the explanation given above but what I am not happy is that the choice (C) talks of "insects going through
a caterpillar stage." and not about "immature caterpillars" as provided in the premise. Now how can we assume that just because an insect goes through the caterpillar stage it could be killed!

Please help me on this.

Thanks.

RadiumBall wrote:Hi All,
I can understand all the explanation given above but what I am not happy is that the choice (C) talks of "insects going through
a caterpillar stage." and not about "immature caterpillars" as provided in the premise. Now how can we assume that just because an insect goes through the caterpillar stage it could be killed!

Please help me on this.

Thanks.

Yes, answer (C) talks of "insects going through a caterpillar stage" and the premise mentions that "immature caterpillars" will be killed by ingesting the enzyme. This is not an issue since any insect going through a caterpillar stage will at some point be an "immature caterpillar". At this point ingesting the enzyme will kill it.

Hi David@VeritasPrep - could you please provide an explanation for this CR in the light of point # 1 & 2 you made above in your post ?

Look forward to your ANALYSIS. Thanks in advance!

Hi David@VeritasPrep - Any update on my above concerns Sir ?

@ Other VeritasPrep Verbal Experts (Dave/Brian) - can any of you please kindly chime in to help me clarify my doubts, if David is NOT available on the forum at this moment ?

Would much appreciate your feedback. Much thanks in advance!

RBBmba@2014 wrote:Hi David@VeritasPrep - Any update on my above concerns Sir ?

@ Other VeritasPrep Verbal Experts (Dave/Brian) - can any of you please kindly chime in to help me clarify my doubts, if David is NOT available on the forum at this moment ?

Would much appreciate your feedback. Much thanks in advance!

Please be patient.
In the US, this Thursday is Thanksgiving.
Today -- the day before Thanksgiving -- is the biggest travel day of the year.
Many people in the US will not be working today through Sunday.

RBBmba@2014 wrote:Hi David@VeritasPrep - could you please provide an explanation for this CR in the light of point # 1 & 2 you made above in your post ?

Look forward to your ANALYSIS. Thanks in advance!

Hi Verbal Experts@Veritas : Can any of you please share your ANALYSIS on the above ?

Look forward to your feedback. Thanks in advance!

P.S: Other Verbal Experts - please feel free to share your thoughts as well!

Hi Verbal Experts@Veritas : Can any of you please share your ANALYSIS on the above ?

Look forward to your feedback. Thanks in advance!

P.S: Other Verbal Experts - please feel free to share your thoughts as well!

David's recommendations (yes, there are two Veritas Davids) were to locate the conclusion and the most important premise.

The conclusion here is in the question itself: it is not advisable to eradicate pests by spraying the enzyme.
The most important premise: the enzyme, when ingested, will kill caterpillars by stopping them from feeding.

So, as Mitch noted, we're looking for a reason why it would be a bad idea to spray this insect-killing enzyme. If the spray also kills beneficial insects, that would be a reason not to use it. This is what C gives us.