Responding to a pm:

Premises:
- Genetically modified vegetable seeds are highly resistant to insect damage.
- They cost more but the cost is likely to decline.
- They need far less pesticide, and most consumers prefer that.

Conclusion: for crops for which these seeds can be developed, their use is likely to become the norm.

A. Whether plant scientists have developed insect-resistant seeds for every crop that is currently grown commercially

Out of scope. The argument clearly discusses only "for crops for which these seeds can be developed". Every crop is not our concern.

B. Whether farmers typically use agricultural pesticides in larger amounts than is necessary to prevent crop damage

This doesn't matter since it will be the same in either case.
GM crops need much less pesticide than do regular crops. Say, GM crops need only 20 kg per acre while regular crops need 100 kg per acre. If farmers do use more pesticides than is necessary, they will use perhaps 110 kg in case of regular crops and 25 kg in case of GM crops. But GM crops will need much less so anyway they will use less than the amount they use in case of regular crops.
If the farmers use only that much pesticide as is necessary, then too they will use much less pesticide in case of GM crops.
So all in all, GM crops are a better deal than regular crops so evaluating this point wouldn't help us judge whether GM crops will be the norm.

C. Whether plants grown from the new genetically engineered seeds can be kept completely free of insect damage

They are much more resistant to insect damage. Whether they will make the crops completely insect-proof, we don't know. It doesn't matter either. Since they are far more resistant, they should become the norm.

D. Whether seeds genetically engineered to produce insect-resistant crops generate significantly lower per acre crop yields than do currently used seeds

The argument discusses the positives of the GM seeds and declares that they will become the norm. But it will be useful to evaluate if they have any shortcomings compared to regular seeds. If their yield is much lower, farmers are likely to not use them since they might earn less than what they earn currently. Hence, this will be useful to evaluate. This will tell us whether GM crops are likely to be the norm.

E. Whether most varieties of crops currently grown commercially have greater natural resistance to insect damage than did similar varieties in the past.

GM crops have much higher resistance as compared with regular crops. Whether the resistance of regular crops has naturally increased over time doesn't matter. GM crops are much more resistant.

Answer (D)
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In this kind of question you're looking for an answer choice that if is true strengthen/weakens the argument and that if is false has weakens/strengthen the argument.

Premise 1: Plant scientists have been able to genetically engineer vegetable seeds
to produce crops that are highly resistant to insect damage

Premise 2: The seeds currently cost more than conventional seeds, their cost is
likely to decline

Premise 3: farmers planting them can use far less pesticide

Premise 4: most consumers prefer vegetables grown with less pesticide

Conclusion : their use is likely to become the norm

The author provides all the evidence to support that the use of the seeds will become a norm


A. Whether plant scientists have developed insect-resistant seeds for every crop that is currently grown commercially

If this is false nothing hampers that the seeds become the norm.
If this is true more seeds will become the norm.

A is out.

B. Whether farmers typically use agricultural pesticides in larger amounts than is necessary to prevent crop damage.

if this is true with the new seeds farmers will need to put less pesticides; the amount decreases
if this is false with the new seeds farmers will need to put less pesticides; the amount decreases even in a greater proportion.
The effect is the same so B is out.

C. Whether plants grown from the new genetically engineered seeds can be kept completely free of insect damage.

if this is true, this strengthens the argument
if this is false, we do not whether the current seeds are completely free of damage (in principle they are not) so no effect

D. Whether seeds genetically engineered to produce insect-resistant crops generate significantly lower per acre crop yields than do currently used seeds.

If this is true perhaps the farmers will want to continue use the current seeds because they produce greater crop per acre
if this is false the argument is strengthen because farmers will want to use the new seeds.

Correct. Two different effects

E. Whether most varieties of crops currently grown commercially have greater natural resistance to insect damage than did similar varieties
in the past.

This does not address the new seeds so is irrelevant.

IMO D

A. Whether plant scientists have developed insect-resistant seeds For every crop that is currently grown commercially -Incorrect. Argument already saying "is likely to become the norm", that means it is still in initial phase of development.
B. Whether farmers typically use agricultural pesticides in larger Amounts than is necessary to prevent crop damage. -Out of scope. The argument just says that "farmers planting them can use far less pesticide". Its "far less" then the normal amount used today, and people will prefer vegetables using less amount of pesticides than the normal amount
C. Whether plants grown from the new genetically engineered seeds Can be kept completely free of insect damage. -Argument already saying that its "highly resistant to insect damage". That means there is still chances, though may be very little, of insect damage.
D. Whether seeds genetically engineered to produce insect-resistant crops generate significantly lower per acre crop yields than do currently used seeds. -Correct. If the new seeds generate significantly low crop yield, then it may become difficult to become a norm.
E. Whether most varieties of crops currently grown commercially have Greater natural resistance to insect damage than did similar varieties in the past. -Irrelevant

Conclusion: Therefore, for crops for which these seeds can be developed, their use
is likely to become the norm.

We need to find out what other information would likely be a deciding factor in arriving at the conclusion above. That additional information could strengthen or weaken the conclusion, either way it should impact the conclusion stated in the stimulus.

Scanning through the options above, option C and D can be narrowed down since the impact the conclusion in some way.

Option C -- Whether plants grown from the new genetically engineered seeds
Can be kept completely free of insect damage.

We have been told in the stimulus that the plants are highly resistant and hence this option is only questioning the premise and not the conclusion.

D. Whether seeds genetically engineered to produce insect-resistant
crops generate significantly lower per acre crop yields than do
currently used seeds.

If the crops were to become the norm then it should at least have the same about of yield. If for some reason the yield is less than what it is currently then these G.M crops could not become the norm. This is the correct option.

Option D.

Experts, kindly assist. My take is B because everything is revolving around B. I find the option as a weakner n strengthener. What is the OA ?

Hii mate,
let me try to clarify my understanding..
i had also selected B at first,then i figured out that option B says,whether farmers at present use more pesticides than required..this option doesnt give us enough proof that they will continue to use more than enough pesticides for genetically engineered seeds as well..so whether there usage currently is more than or less than required is not enough to strenghthen or weaken the arguement..On the other hand,as per D,if the farm is not providing atleast equal productivity than before,then it creates enough doubts whether use of G.engineered seeds will become a norm..OA- D


Hope that clears
Please consider KUDOS if my post helped..
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Plant scientists have been able to genetically engineer vegetable seeds to produce crops that are highly resistant to insect damage.
Although these seeds currently cost more than conventional seeds, their cost is likely to decline.
Moreover, farmers planting them can use far less pesticide, and most consumers prefer vegetables grown with less pesticide,
therefore, for crops for which these seeds can be developed, their use is likely to become the norm.

Which of the following would be most useful to know in evaluating the argument above?

A. Whether plant scientists have developed insect-resistant seeds For every crop that is currently grown commercially
>> Doesn't help to confirm the conclusion.
B. Whether farmers typically use agricultural pesticides in larger Amounts than is necessary to prevent crop damage.
>> Variance Yes/No.
Both the cases doesn't help much to compare the pesticide usage with normal plants and with genetically modified plants.
C. Whether plants grown from the new genetically engineered seeds Can be kept completely free of insect damage.
>>Yes/No.
Case with "No". We don't know how much can they save. It can be 80% or 40% of total crop.So not conclusive
D. Whether seeds genetically engineered to produce insect-resistant crops generate significantly lower per acre crop yields than do currently used seeds.
>> Correct.
Case Yes: Oops then it put doubts on the conclusion that the seeds use is likely to become the norm.
Case No: Cool. Then with all the above mentioned benefits, this is another adv, which rules out a factor that can weaken the arg.
E. Whether most varieties of crops currently grown commercially have Greater natural resistance to insect damage than did similar varieties in the past.
>> Doesn't help to confirm the conclusion.

Premise: Plant scientists have been able to genetically engineer vegetable seeds to produce crops that are highly resistant to insect damage and at present they are costly, but the costs will reduce in future:
Conclusion: These seeds will ve vastly used in the future.

We need to evaluate this conclusion. If we ask questions such as the yield of the seeds or the life of the crops etc. we can determine whether more farmers will use the seeds.
Option D asks the same question about the yield. If the new seeds produce low crops, then farmers might not use them

Does this help?

Thank you, OptimusPrepJanielle,

I chose B because I attacked wrong target (the validity of the evidence) rather than focus on the conclusion.

One more question, what should we do when meet an Evaluate The Argument? Pre-think a potential questions? Find a flaw in the reasoning? Or just start to go through 5 answer choices?

Thank you very much

Pre thinking is always the best way to go forward in CR.
It gives you a direction in which you should think to solve the question.

Hi OptimusPrepJanielle / chetan2u ,

Can you please assist.

Thanks
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Hi PrakharGMAT,
since you are looing at B, let me tell you Why it should not be the answer..



Yes, you are correct that they will use excess pesticides. But if he is used to using larger amounts, it was existing earlier too and now also..
AND when you read the choice, the stress in the option should be on THAN IS NECESSARY...

this means earlier if he required 100 kgs for a specific area, he was using 120 kgs....
Now ONLY 10 kgs is necessary, he will use 12 kgs..

Still it will be lesser than previous times and people will prefer it..


Yes, if the choice said -- Whether farmers typically use same amount of agricultural pesticides to prevent crop damage irrespective of type of seeds...
This coud have been a valid answer
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Plant scientists have been able to genetically engineer vegetable seeds to produce crops that are highly resistant to insect damage. Although these seeds currently cost more than conventional seeds, their cost is likely to decline. Moreover, farmers planting them can use far less pesticide, and most consumers prefer vegetables grown with less pesticide, therefore, for crops for which these seeds can be developed, their use is likely to become the norm.

which of the following would be most useful to know in evaluating the argument above?

Premise :- The New seeds with all the awsome features
Conclusion :- Will be the Norm

Assumption :- For a crop to be a norm it has to be insect resistant and no other factor comes into play

A. Whether plant scientists have developed insect-resistant seeds For every crop that is currently grown commercially :- Irrelevant, rather explicitly stated in the stimuli
B. Whether farmers typically use agricultural pesticides in larger Amounts than is necessary to prevent crop damage.:- Irrelevant
C. Whether plants grown from the new genetically engineered seeds Can be kept completely free of insect damage. :- Irrelevant
D. Whether seeds genetically engineered to produce insect-resistant crops generate significantly lower per acre crop yields than do currently used seeds. :- Yes the introduction of new factor, saying Yes will destroy the stimuli and saying no it will strengthen it
E. Whether most varieties of crops currently grown commercially have Greater natural resistance to insect damage than did similar varieties in the past. Irrelevant

B vs D

Conclusion: Crops for which GEV seeds can be developed, their (GEV Seeds) use is likely to become the norm.

As per B, farmers are using pesticides in greater amount, more than required to control pests.
In one of the premises, it's given that by using new seeds, farmers will be using 'far less' pesticides.
So,let's say farmers were using 100kg of pesticides earlier for normal seeds and now by using GEV seed, they may use 20kgs of pesticide (FAR LESS than normal seed).
As per B, that 100kg was greater than the amount required to control pests. So,ideally if 80kg was required to control pests, farmers were using 100kgs. Now, We already know from the given premise that by using GEV seeds, the pesticide consumption will go down to let's say 20kg (far less than 100kgs)...therefore this info that farmers are using 20 kgs extra is not weighing this fact down that the GEV seeds are making the consumption down to 20 kgs. Nor does, it aids this fact. Therefore, this option is not even worth applying variance test.

If I were to say, farmers were using 100kgs of fertilizers for normal seeds, out of which only 80 kgs was required to control pests AND by using GEV seeds farmers are using 80 kgs of fertilizers...then we can say GEV seeds are not that beneficial as they are not significantly impacting the consumption of fertilizers. The beauty of this option is that it makes you think this way and if you fail to read 'FAR LESS' in the stimulus then it's likely that you might end up choosing this option!

Option D is far more convincing as it says GEV generates SIGNIFICANTLY LOWER yields than normal crops. If it's true, then GEV seeds will not be a NORM (Unless Farmers are willing to bear the loss ) so we got a weakner...and if it's false then GEV seeds are going to be NORM (due to various Pros mentioned in the stimulus)...so we got a strengthener. Therefore, this option clears the variance test with flying colors

KarishmaB - While I agree D is the OA -- would you agree (D) does miss something very specific ? Specifically -

It doesnt talk about the assumption between the premise and the conclusion specifically.

The premises to make the conclusion were about - cost and usage of pesticide ONLY

Now bringing another factor (yield) can technically be considered wrong because it doesnt touch on the 'relationship' between the specific premises and the conclusion

Thoughts

I am not sure why you think "useful to evaluate" must bring some 'assumption' forth.
Normally, in these arguments, the conclusions are sweeping statements based on limited facts. We need more information to evaluate the statement. So the correct option makes us question the important points missed by the argument.

e.g.

Plan A is cheap, effective and clean for the environment.
Conclusion: It is the best plan for us.

Useful to evaluate: Plan A will cut down our workforce to half. Is that acceptable to us?

It will often bring in a factor ignored by the argument but relevant for the conclusion. Just focus on the conclusion and think about what all can be relevant to it.
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