A commercial insect trap consists of a small box containing pesticide

Question

Competition Mode Question

A commercial insect trap consists of a small box containing pesticide mixed with glucose, a sweet substance known to attract insect pests. Yet in households where this type of trap has been used regularly for the past several years, recently installed traps are far less effective in eliminating insect pests than were traps of that type installed several years ago. Research scientists have hypothesized that traps in those households decreased in effectiveness because successive generations of the pests developed a resistance to the pesticide in the traps.

Which one of the following, if true, most seriously undermines the hypothesis?

Which one of the following, if true, most seriously undermines the hypothesis?

(A) In households where the traps have been used regularly, the proportion of insect pests that have a natural aversion to eating glucose has increased with each successive generation.

(B) Even when only a few individuals out an entire generation of insects survive the effects of a pesticide, the offspring of those individuals are usually resistant to that pesticide.

(C) After eating glucose mixed with the pesticide, insects that live in households that do not use the trap tend to die in greater numbers than do insects from households where the traps have been used regularly.

(D) After the manufacturer of the traps increased the concentration of the pesticide used in the traps, the traps were no more effective in eliminating household insect pests than were the original traps.

(E) The kind of glucose used to bait the traps is one of several different kinds of glucose that occur naturally.

Krishh9119 · Answer

Hypothesis:Research scientists have hypothesized that traps in those households decreased in effectiveness because successive generations of the pests developed a resistance to the pesticide in the traps.

Question Type:  Weaken .

Pre thinking: Traps in those households decreased in effectiveness  not because of 'resistance to the pesticide'  BUT because of some other reason.

(A) In households where the traps have been used regularly, the proportion of insect pests that have a natural aversion to eating glucose has increased with each successive generation.
 Strengthener

(B) Even when only a few individuals out an entire generation of insects survive the effects of a pesticide, the offspring of those individuals are usually resistant to that pesticide.
 weak Strengthener

(C) After eating glucose mixed with the pesticide, insects that live in households that do not use the trap tend to die in greater numbers than do insects from households where the traps have been used regularly.
  Wow ,this suggests that 'Trap' is the issue BUT not the ' glucose mixed with the pesticide'.

(D) After the manufacturer of the traps increased the concentration of the pesticide used in the traps, the traps were no more effective in eliminating household insect pests than were the original traps.
 Strengthener

(E) The kind of glucose used to bait the traps is one of several different kinds of glucose that occur naturally.
 Out of Scope

Our answer is C.

ArunSharma12 · Answer

Commercial insect trap is effective when glucose attracts pests and then pesticide kills the pests.
If pests have not developed resistance to the pesticides then they might have developed dislike for the glucose, thereby lowering the effectiveness of trap.

(A) In households where the traps have been used regularly, the proportion of insect pests that have a natural aversion to eating glucose has increased with each successive generation.
 This describes with each generation pests aversion has increased, so they are no more attracted to these traps.

(B) Even when only a few individuals out an entire generation of insects survive the effects of a pesticide, the offspring of those individuals are usually resistant to that pesticide.
 How the offspring builds resistance is not relevant to the reasoning

(C) After eating glucose mixed with the pesticide, insects that live in households that do not use the trap tend to die in greater numbers than do insects from households where the traps have been used regularly.
 This indicates another reason for pest deaths but this does not explain whether effectiveness of these traps are reduced.

(D) After the manufacturer of the traps increased the concentration of the pesticide used in the traps, the traps were no more effective in eliminating household insect pests than were the original traps.
 increased dosage of pesticides highlights the strong resistance of these pests. This strengthens the argument

(E) The kind of glucose used to bait the traps is one of several different kinds of glucose that occur naturally.
 This is not relevant to the reasoning 
Ans: A

chaitralirr · Answer

A commercial insect trap consists of a small box containing pesticide mixed with glucose, a sweet substance known to attract insect pests. Yet in households where this type of trap has been used regularly for the past several years, recently installed traps are far less effective in eliminating insect pests than were traps of that type installed several years ago. Research scientists have hypothesized that traps in those households decreased in effectiveness because successive generations of the pests developed a resistance to the pesticide in the traps.

Which one of the following, if true, most seriously undermines the hypothesis?

Stimulus: commercial insect traps used a small box of glucose to attract insects it was found that the new traps was not as useful as the old traps. Research scientists believe that this could be due the resistance developed by insects in the traps. IMO D states that they changed the concentration of glucose and so it is ineffective not that the insects have developed resistance.

Which one of the following, if true, most seriously undermines the hypothesis?

(A) In households where the traps have been used regularly, the proportion of insect pests that have a natural aversion to eating glucose has increased with each successive generation.

(B) Even when only a few individuals out an entire generation of insects survive the effects of a pesticide, the offspring of those individuals are usually resistant to that pesticide.

(C) After eating glucose mixed with the pesticide, insects that live in households that do not use the trap tend to die in greater numbers than do insects from households where the traps have been used regularly.

(D) After the manufacturer of the traps increased the concentration of the pesticide used in the traps, the traps were no more effective in eliminating household insect pests than were the original traps.

(E) The kind of glucose used to bait the traps is one of several different kinds of glucose that occur naturally.

KarishmaB · Answer

Premises: A commercial insect trap consists of pesticide + glucose Where this type of trap has been used regularly for the past several years, recently installed traps are far less effective than were old traps Hypothesis: Traps in those households decreased in effectiveness because successive generations of the pests developed a resistance to the pesticide in the traps. The hypothesis tells us that the reason for less effectiveness is a resistance to the pesticide. We need to weaken this. So we need to say that no, something else is the reason. (A) In households where the traps have been used regularly, the proportion of insect pests that have a natural aversion to eating glucose has increased with each successive generation. This option tells us that the insects have developed an aversion to glucose. So this means that the pesticide may not be the problem. The traps may not be working because insects don't want to eat the glucose so they are not eating the bait. Then the reason may not be that they are immune to pesticide now. This is correct. (B) Even when only a few individuals out of an entire generation of insects survive the effects of a pesticide, the offspring of those individuals are usually resistant to that pesticide. All this tells us is that offsprings of immune insects are immune. It doesn't tell us whether the number of immune insects is growing or reducing over time. Even if it did imply that from generation to generation, more insects are becoming immune, it will strengthen our argument. Eliminate. (C) After eating glucose mixed with the pesticide, insects that live in households that do not use the trap tend to die in greater numbers than do insects from households where the traps have been used regularly. If anything, it supports that insects in the houses in which traps have been used for a long time have become immune. The same traps are effective in new houses but less effective in old. Why? Because in old houses insects are immune to the pesticide. This (D) After the manufacturer of the traps increased the concentration of the pesticide used in the traps, the traps were no more effective in eliminating household insect pests than were the original traps. It seems to suggest that the pesticide has become ineffective. It doesn't matter how much you put it, it is still not having any effect. It does seem that the pests have become immune to this pesticide. (E) The kind of glucose used to bait the traps is one of several different kinds of glucose that occur naturally. Irrelevant. Doesn't say what the reason for ineffectiveness is. Answer (A) Discussion on Weaken Questions: https://youtu.be/EhZ8FKkfy0k

RJ3001274402 · Answer

I interpreted option D as following:

An increase in the concentration of the pesticide results in a decrease in the concentration of glucose, which serves as the bait. As a result, the reduced glucose concentration is less effective in attracting pests, thereby diminishing the overall effectiveness of the trap

Can someone point out the mistake in my reasoning?

unraveled · Answer

Conclusion is only about pesticide not glucose. So, anything that happened as far as glucose is concerned becomes irrelevant for this question stem. IN D, overall it is saying the same thing that passage concludes about i.e. reduced effectiveness of the traps as insect developed resistance to the pesticides. So, this means it does not weaken the conclusion.

A, on the other hand, gives altogether another perspective to the passage. The insects developing natural aversion to pesticides is totally different from developing resistance to the pesticides. Subtle language change with meaning of words.

Answer A.

Jayant9090 · Answer

I selected "D".

(D) After the manufacturer of the traps increased the concentration of the pesticide used in the traps, the traps were no more effective in eliminating household insect pests than were the original traps.

I assumed, here, that higher concentration made Glucose trap a bit less ineffective because of strong pesticide taste or smell. Hence, at least a mild weakener.

DmitryFarber · Answer

We'd have to be told that the increase led to a change in taste or smell. For all we know, it could be a difference of 2% vs. 1.5%, with no noticeable odor! In any case, that wouldn't explain why these traps are "no more effective," but in houses where traps have been in use for several years, they are "far less effective."

Jayant9090 · Answer

Thanks Dmitry

! Missed the difference of 2% vs. 1.5% logic. I was taking it to extremes only.

A commercial insect trap consists of a small box containing pesticide

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A commercial insect trap consists of a small box containing pesticide

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