Potato cyst nematodes are a pest of potato crops. The nematodes can li

Question

Potato cyst nematodes are a pest of potato crops. The nematodes can lie dormant for several years in their cysts, which are protective capsules, and do not emerge except in the presence of chemicals emitted by potato roots. A company that has identified the relevant chemicals is planning to market them to potato farmers to spread on their fields when no potatoes are planted; any nematodes that emerge will soon starve to death.

Which of the following, if true, best supports the claim that the company's plan will be successful?

(A) Nematodes that have emerged from their cysts can be killed by ordinary pesticides.

(B) The only part of a potato plant that a nematode eats is the roots.

(C) Some bacteria commonly present in the roots of potatoes digest the chemicals that cause the nematodes to emerge from their cysts.

(D) Trials have shown that spreading even minute quantities of the chemicals on potato fields caused nine-tenths of the nematodes present to emerge from their cysts.

(E) the chemicals that cause the nematodes to emerge from their cysts are not emitted all the time the potato plant is growing.

GMATNinja · Accepted Answer

Let's revisit the "company's plan," and then see how it will be affected by answer choice (B).

The company's plan is to "market   to potato farmers to spread on their fields when  no potatoes are planted. " The company expects this to be successful because "any nematodes that emerge will soon starve to death." So, instead of emerging when potatoes are planted and eating the potato crop, the nematodes will emerge when the chemicals are spread and there are no potatoes to eat. The nematodes will then starve to death in the absence of potatoes to eat.

Hm, that's not a great time to be a nematode.

Now let's analyze (B) in the context of this plan:

The passage mentions roots in saying that nematodes "do not emerge except in the presence of chemicals  emitted by potato roots. " The company has identified these chemicals and is using them to lure nematodes out of their protective capsules when there are no potatoes in the field. However, does it matter which part of the potato plant is actually  eaten  by the nematodes? We know that nematodes are a "pest of potato crops" -- in other words, they cause harm to the crop in some way. Whether that harm is because they eat the roots, the leaves, or any other part of the potato plant is irrelevant to the success of the company's plan. You can eliminate (B) for this reason.

Answer choice (D), in the other hand, clearly supports the claim that the company's plan will be successful:

The company's plan depends on nematodes emerging from their cysts when the chemicals are spread. These trials show that nine-tenths of the nematodes do exactly that. (D) is the correct answer.

I hope that helps!

piyush26 · Answer

Key points from the passage:

1. The company has identified the chemicals responsible for the emerging of nematodes.
2. The company is planning to market these ‘chemicals’ to the farmers, NOT the nematodes.
3. The company wants the farmers to spread these chemicals on their fields when no potatoes are planted. (So that, the nematodes which will emerge do not damage the potato crops)
4. The company claims that any nematodes that will emerge because of spreading the chemicals, will starve – They will starve because they have no food. (Potato fests feed only on potatoes – This is an implicit assumption)

Basically, the company’s plan is to activate the dormant nematodes that are already there in the farm. The company plans to activate the nematodes when there are no potato plants in the farm, so that the nematodes thus activated do not have any food to eat, and hence starve to death.

Now, please note that if the chemicals are unable to activate most of the nematodes (more than 75%), then the company’s plan fails.

Therefore, OA D is correct – Since this option states that the chemicals, even when sprayed in small quantities are able to activate 90% of the nematodes.

If this were an assumption question – OA B would be correct.

Hope this helps!!

mymba99 · Answer

Company's claim: Because of our chemicals , nematodes will soon starve to death.
We want to support their claim.
A - this is opposite answer. It says nematodes die because of pesticides. But the claim is nematodes will die because of starvation. Out
B - This may be tempting but it is very far away from the claim. It does not talk about chemicals, nor does it talk about how nematodes die. It is simply putting forward one of the characteristics of nematodes. Out of scope.
C - out
D - minute quantities -- nine tenths of nematodes emerge.
This choice is directly addressing the claim. It is clearly repeating what company has claimed.
Company said , hey our chemicals makes nematodes come out..
Trials proved , hey using MINUTE quantities of chemicals make 90% of nematodes to emerge.
D is my choice
E chemicals ...not emitted..(makes no sense to me) Out.

Sunny143 · Answer

I am going with D as well...wats the OA?

abhijit_sen · Answer

Premise1: Potato cyst nematodes are a pest of potato crops. 
Premise2: The nematodes can lie dormant for several years in their cysts, which are protective capsules, and 
Premise3: The Nematodes do not emerge except in the presence of chemicals emitted by potato roots. 
Premise4: A company that has identified the relevant chemicals in planning to market them to potato farmers to spread on their fields when no potatoes are planted; 
Conclusion: any nematodes that emerge will soon starve to death.

(A) Nematodes that have emerged from their cysts can be killed by ordinary pesticides.
This is against conclusion, which says nematodes will die because of starvation. So even if nematodes can be killed by pesticides but this is not strengthening the passage.

(B) The only part of a potato plant that a nematode eats is the roots.
Premise3 implies tells that roots release certain chemicals that make nematodes active. Premise 4 tells company has developed similar chemical and it needs to be spread while there is no potatoes in the field. As this sentence implies if nematodes only eats roots of potato plant. But as this company produced chemical make nematodes active and when they found nothing to eat as potato fields are not ready. So chemical is tricking nematodes. This strengthen the case successfully. Note that this sentence is joining two premises as well as focusing on conclusion so strongest contender.

(C) Some bacteria commonly present in the roots of potatoes digest the chemicals that cause the nematodes to emerge from their cysts.
If at all this will weaken the case. Because bacteria is also present when potatoes are there in the field.

(D) Trials have shown that spreading even minute quantities of the chemicals on potato fields caused nine-tenths of the nematodes present to emerge from their cysts.
This is good alternative that tells that 90% of nematodes will come out. But do they die because of starvation how is this strengthening the conclusion.

(E) the chemicals that cause the nematodes to emerge from their cysts are not emitted all the time the potato plant is growing. 
Premise4 says that chemical is spread only when there is no potatoes in field, so this option is irrelevant.

vnigam21 · Answer

(A) Nematodes that have emerged from their cysts can be killed by ordinary pesticides.  This is irrelevant to the plan. As the plan is talking about the use of the chemical emitted by potato roots. Ordinary Pesticides are not in picture anywhere.

(B) The only part of a potato plant that a nematode eats is the roots.  This statement also has nothing to do with the plan. Whatever part of the potato plant the nematode eats does not support the company's plan of marketing chemical to the farmers.

(C) Some bacteria commonly present in the roots of potatoes digest the chemicals that cause the nematodes to emerge from their cysts.  Here we can consider two points, firstly, the chemical is planned to be spread on the fields when no potato plant is planted, so this statement of option C does not come into picture. As no plant, no root, no bacteria. Secondly, the chemical is spread explicitly by the farmers, we are not dependent entirely on the chemical emitted by potato roots.

(D) Trials have shown that spreading even minute quantities of the chemicals on potato fields caused nine-tenths of the nematodes present to emerge from their cysts.   As per this finding majority of nematodes will be starving to death.

(E) the chemicals that cause the nematodes to emerge from their cysts are not emitted all the time the potato plant is growing.  This statement maybe true about the release of chemicals during potatoes growth lifecycle, but we are concerned with the chemicals explicitly spread by the farmers before the potatoes are planted

Thus, only option D remains and is the final answer.

XyLan · Answer

Premise1: Potato cyst nematodes are a pest of potato crops. 
Premise2: The nematodes can lie dormant for several years in their cysts, which are protective capsules, and 
Premise3: The Nematodes do not emerge except in the presence of chemicals emitted by potato roots. 
Premise4: A company that has identified the relevant chemicals in planning to market them to potato farmers to spread on their fields when   no potatoes are planted ; 
 Conclusion: any nematodes that emerge will soon starve to death.

According to Premise4,  Company's Plan: To eliminate the pests before potatoes are planted, i.e, apply the relevant chemicals to bring the pests out of their protective capsules without the potato crops.

To Strengthen the argument, we need to show that the Company's plan will be successful/near to successful.

(A) Nematodes that have emerged from their cysts can be killed by ordinary pesticides. 
 This is irrelevant to the plan. As the plan is talking about the use of the chemical emitted by potato roots. Ordinary Pesticides are not in picture anywhere.

(B) The only part of a potato plant that a nematode eats is the roots. 
 This statement has nothing to do with the plan. 
The company's plan is to eliminate the pests   before plantation of potatoes .
 Whatever part of the potato plant the nematode eats does not support the company's plan of marketing chemical to the farmers.

(C) Some bacteria commonly present in the roots of potatoes digest the chemicals that cause the nematodes to emerge from their cysts.

(D) Trials have shown that spreading even minute quantities of the chemicals on potato fields caused nine-tenths of the nematodes present to emerge from their cysts.
 As per this finding majority of nematodes will be starving to death.

(E) the chemicals that cause the nematodes to emerge from their cysts are not emitted all the time the potato plant is growing.
 This statement may be true about the release of chemicals during potatoes growth lifecycle, but we are concerned with the chemicals explicitly spread by the farmers before the potatoes are planted

Thus, only option D remains and is the final answer.

dave13 · Answer

Potato cyst nematodes are a pest of potato crops. The nematodes can lie dormant for several years in their cysts, which are protective capsules, and do not emerge except in the presence of chemicals emitted by potato roots. A company that has identified the relevant chemicals in planning to market them to potato farmers to spread on their fields when no potatoes are planted; any nematodes that emerge will soon starve to death.

Which of the following, if true, best supports the claim that the company's plan will be successful?

What is the main concern ? To get rid of nematodes by starving them to death. nematodes are spread accross potato fields

(A) Nematodes that have emerged from their cysts can be killed by ordinary pesticides.  ( out of scope. pestices not mentioned.

(B) The only part of a potato plant that a nematode eats is the roots.  ( out of scope. we dont know this.)

(C) Some bacteria commonly present in the roots of potatoes digest the chemicals that cause the nematodes to emerge from their cysts.  ( out of scope. tals about some other bacteria. ) 
 
(D) Trials have shown that spreading even minute quantities of the chemicals on potato fields caused nine-tenths of the nematodes present to emerge from their cysts.   ( true. matches the plan. nematodes will emerge from potato fileds and starve to death. )

(E) the chemicals that cause the nematodes to emerge from their cysts are not emitted all the time the potato plant is growing.  out of scope. we dont know this

D by POE

AbhimanyuDhar · Answer

Hi Experts  GMATNinja ,

I would present my analysis so that you could see gap in my understanding .

I understood the argument, but couldn't figure out between B and D. 
Well the argument is that, 
chemical ( similar to that of emitted by potato roots) which makes these pests emerge , will make these pests emerge , and these pests ,in absence of potato crop,will die of starvation.

Can i infer that if there were potato crop then they would survive after they would have emerged from their protective shells.

So basically , if we have a statement that these pests once emerged out of cyst , survive only in presence of potato crop, then we can say that yes authors claim is strengthened.

So B is very close to what i was thinking.

But D says Test experiments on fields have shown that these chemicals were successful in killing 90% of pests.

But i guess GMAT has different plans, and wants me to focus more on my mistakes. 
So looking for learning what went wrong in this question?

I read somewhere that "Assumption can be a strengthener but strengthener need not be an Assumption"

Many have suggested that B is assumption and D is strengthener. If this is true then i have a major issue in approaching these type of questions.

Thanks 
AD

mSKR · Answer

HI  VeritasKarishma   AndrewN   GMATNinja

For this question, I find some gap in D and choose A based on below reasoning

As it is mentioned that Nematodes will starved to death but no where in the argument mentioned that relevant chemicals can starve these nematodes to death, So if these nematodes come out of their cysts then it may not be necessary that same chemicals will starve them to death. The reasoning behind this thinking : With the same chemicals they have come out of cysts but were not starved to death instead damaged the crops. So this time also , why would i assume that they would be dead when with same chemicals they had come before and harmed the crop and went back to cysts. It means the key problem is to bring them out . In this way, any pesticide can kill these nematodes ,as they just don't need to come out. That's I chose A

I shortlisted D because they usually come out once in years . and this time in trials 9 out of 10 . But it doesn't mean they would starve to death because D option didn't mention that 9 out 10 nematodes came out and were starved to death. Due to this gap, I rejected D and finally choose A.

Please share your comments on my reasoning .

KarishmaB · Answer

You might need to read the argument 2-3 times carefully to understand exactly what it says:

Potato cyst nematodes are a pest of potato crops. The nematodes can lie dormant for several years in their cysts, which are protective capsules, and do not emerge except in the presence of chemicals emitted by potato roots. 
 
Nematodes are pests that reside inside their cyst in the soil. They do not come out except in the presence of specific chemicals emitted by potato roots (when potatoes are planted in that soil).

A company that has identified the relevant chemicals in planning to market them to potato farmers to spread on their fields when no potatoes are planted; any nematodes that emerge will soon starve to death. 
 
A company has identified these chemicals. They will sell them commercially so that farmers can spread these chemicals on their fields (when there are no potatoes). The expectation is that nematodes will then come out (because they will assume that there are potatoes around). Once they come out, they are expected to starve to death (because actually there are no potatoes).

What will help in making the plan successful?

(A) Nematodes that have emerged from their cysts can be killed by ordinary pesticides.

Irrelevant. They are anyway expected to starve.

(B) The only part of a potato plant that a nematode eats is the roots.

This is again irrelevant. Whether the nematode eats the roots or the stem etc doesn't matter. There will be no potatoes to eat so it will starve.

(C) Some bacteria commonly present in the roots of potatoes digest the chemicals that cause the nematodes to emerge from their cysts.

This is irrelevant. We are given that nematodes emerge when some chemicals are secreted by potato roots. What happens to the chemicals thereafter, we don't know.

(D) Trials have shown that spreading even minute quantities of the chemicals on potato fields caused nine-tenths of the nematodes present to emerge from their cysts.

Most nematodes come out with even minute amounts of chemicals. This means that most of the pests will come out and starve. Hence, when we plant our potato crop, there will be no nematodes to spoil it.

(E) the chemicals that cause the nematodes to emerge from their cysts are not emitted all the time the potato plant is growing.
 
Irrelevant. We are planning on introducing the chemical on the field when there are no potatoes.

Answer (D)

*Edited

mSKR · Answer

I realized the gap in understanding. 
It seems these nematodes are safe in their cysts , possibly can survive longer without eating. But as soon as they come out , they may not be able to go back in their cysts and hence starve to death outside. 
( the conclusion in argument is given up to here)

I just wonder what made them not go back and how could they survive for so long.
On googling, i found: their eggs can survive in their cysts for up to 20 years. These nematodes find host cells to feed off . they remain in the soil until they find another suitable host beginning the cycle again. So if no potatoes in field then they maybe surviving on other hosts and get access to roots of plants. Here emerging means emerged from egg . With new form of life, they need some host cells , so without host cells they would starve to death.

Now I am pretty clear with this argument. I realized I overlooked meaning of some key words in my reading , that's why got wrong. Thanks  VeritasKarishma

Nina1987 · Answer

GMATNinja  but isnt D already mentioned in the passage that the relevant chemical which makes todes come out of capsules has been identified by the company? I thought this was already established in the passage and hence I eliminated it

GMATNinja · Answer

(D) actually gives us a lot of new information.

From the passage, we know that "nematodes... do not emerge except in the presence of chemicals emitted by potato roots." So, when the chemicals are NOT present, the nematodes do NOT emerge.

That's not the same as saying that when the chemicals ARE present, the nematodes ALWAYS emerge. It could be that only small portions of the nematodes emerge at a time, which might be an issue for the company's plan -- it could be that farmers spread the chemicals, but there are still tons of nematodes ready to emerge during potato season.

(D) helps close that gap by telling us that a very high proportion of nematodes  do  emerge when the chemicals are present.

Additionally, (D) tells us that this occurs even when " minute  quantities" of the chemicals are spread. This is another clue that the company's plan is a good one -- after all, if it took very large quantities of the chemical to cause the nematodes to come out, then perhaps the plan wouldn't be viable. (D) closes this gap as well.

That's why (D) is the correct answer.

I hope that helps!

ARSarkar · Answer

The plan : A company that has identified the relevant chemicals is planning to market them to potato farmers to spread on their fields when no potatoes are planted; any nematodes that emerge will soon starve to death.
The plan is the conclusion. We need to strengthen it. 
As per the plan, the chemicals will be spread before the potato plantation. So how do we know that the nematodes will soon starve to death?
Option B tells that the nematodes eat only the root and since the potatoes are not planted, they will not have anything to eat and they will die of starvation.  Hence B is the correct

Option D tells that only a small quantity is required to make the nematodes come out of their cyst. That means the chemicals are effective. Does it mean that the nematodes will starve to death? After coming of the cyst it can eat from sun lights or from nutrients present in the soil.  Hence D is wrong.

On the basis of this analysis, I chose B. Kindly help me to understand gap in my logic.  GMATNinja   KarishmaB   mysterymanrog

Regards,
Sarkar

KarishmaB · Answer

Request you to please read my explanation of the argument above first: https://gmatclub.com/forum/potato-cyst- ... l#p2753304 I have edited it. Now consider this: We are given that the chemical will be spread when there are no potatoes in the field. So the nematodes will be misguided into emerging thinking there are potatoes in the field. Whether they were going to eat the roots of the potato or the stem or the leaves, doesn't matter. They get nothing of potatoes and they starve. Option (B) doesn't help our plan. We are given that nematodes eat potatoes. We cannot assume that there are other sources of food present in the field. They will emerge and since the potatoes will not be there, they will starve. Hence (D) strengthens our plan. If even a little quantity of the chemical is enough to make them emerge, most likely almost all of them should emerge when t he chemical is spread on the empty field.

ARSarkar · Answer

Thank you for the explanation.

Raman109 · Answer

Understanding the argument - 
The goal is to get the pests out of their cysts - once out of the cyst, they will starve to death. 
The plan is to spread the chemical on the fields when no potatoes are planted.

Prethinking 
How can we bolster the argument - 
1. First, we need to ensure that the chemical works as planned. The pests come out of cysts after farmers spread the chemical. 
2. They don't live for long once the pests are out.

What are the pointers that will weaken it (so that we can guard the argument against those weakeners) 
1. What if the chemical doesn't work as planned, and only the minutest of the pests come out and the rest stay intact? We can't say they'll not come out as that'll be against the premise 
2. What if they live for a year or more once they are out?

Option Elimination -

(A) Nematodes that have emerged from their cysts can be killed by ordinary pesticides. - Here, we are talking about another plan. Our scope is limited to the plan goal shared in the argument. Any alternate plan to reach the goal is out of scope.

(B) The only part of a potato plant that a nematode eats is the roots. - Doenst matter. Out of scope.

(C) Some bacteria commonly present in the roots of potatoes digest the chemicals that cause the nematodes to emerge from their cysts. - It's talking about the process but our scope is limited to strengthening the shared plan-goal. This is out of scope.

(D) Trials have shown that spreading even minute quantities of the chemicals on potato fields caused nine-tenths of the nematodes present to emerge from their cysts. - Perfect. In line with our pre-thinking. It means the plan works.

(E) the chemicals that cause the nematodes to emerge from their cysts are not emitted all the time the potato plant is growing. - Does not matter. Out of scope.

rmahe11 · Answer

Wont D weaken the argument , since more than 50 percent of nematodes emerge from the cyst ? as it says (9/10 th)

Potato cyst nematodes are a pest of potato crops. The nematodes can li

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GMAT Critical Reasoning (CR) Questions

Potato cyst nematodes are a pest of potato crops. The nematodes can li

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