The sustained massive use of pesticides in farming has two effects tha

Question

The sustained massive use of pesticides in farming has two effects that are especially negative. First, it often kills off the pests' natural enemies in the area. Second, it often unintentionally gives rise to insecticide-resistant pests, since those insects that survive a particular insecticide will be the ones most resistant to it, and they are the ones left to breed.

From the passage above, it can be properly inferred that the effectiveness of the sustained massive use of pesticides can be extended by doing which of the following, assuming that each is a realistic possibility?

From the passage above, it can be properly inferred that the effectiveness of the sustained massive use of pesticides can be extended by doing which of the following, assuming that each is a realistic possibility?

(A) Using only chemically stable insecticides

(B) Periodically switching the type of insecticide used

(C) Gradually increasing the quantities of pesticides used

(D) Leaving a few fields fallow every year

(E) Breeding higher-yielding varieties of crop plants

ID: 500314
CR07612

pqhai · Accepted Answer

Fact:   sustained   massive use of pesticide ==> kills off the pest's enemies & give rise to insecticide-resistant pests
Conclusion: those insects survive   a particular insecticide   ==> the ones left to breed

Because pests can resist a particular insecticide ONLY IF this insecticide is used over and over again . 
To prevent the pests from resisting a particular insecticide, the most effective way is to change type of insecticide used.

B says exactly how to prevent pests from resisting insecticide.

Hence, B is correct.

BukrsGmat · Answer

The sustained massive use of pesticides in farming has two effects that are especially pernicious. First, it often
kills off the pests' natural enemies in the area . Second, it often unintentionally gives rise to insecticide-resistant
pests, since those insects that  survive a particular insecticide  will bethe ones most resi stantto it, and they are
the ones left to breed.

From the passage above, it can be properly inferred that the effectiveness of the sustained massive use of
pesticides can be extended by doingwhich of the following, assuming that each is a realistic possibility?

survive a particular insecticide ...so massive use can only be extended if we can attack this "particular type insecticide"

(Al Using only  chemically stable  insecticides  new knoweldge -ignore 
(B) Periodically  switching thetype of  insecticide used ->correct :there are changing it..so if that pesticide survived by one type chances r it will be killed by other type 
(C) Gradually  increasing the quantities  of pesticides used the stronger ones can resist the higher quantity 
(D) Leavinga few fields fallow every year does not help us 
(E) Breeding higher-yielding varieties of crop plants u need a ans discussing about pesticide

so B

ssbisht · Answer

Argument: 
Sustained massive use of pesticides in farming has two effects
1. it often kills off the pests' natural enemies in the area
2. it often unintentionally gives rise to insecticide-resistant pests , since those insects  that survive a particular insecticide will be the ones most resistant to it , and they are the ones left to breed.

Pre thinking: 
Sustained use kills natural enemies.
Sustained use of a particular pesticide wills make insects that survives as resistant to that pesticide.
So by using one pesticide for too long we are actually creating insects resistant to that pesticide. Hence a way to avoid this is not to use one particular pesticide for too long.

Analysis of answer choice 
(Al Using only chemically stable insecticides
INCORRECT: Irrelevant as chemical stability is not a problem here.
(B) Periodically switching the type of insecticide used
 CORRECT: Since using one particular pesticide makes insects resistant to it so a better approach would be to change pesticides so that insects which develops resistance against one type gets killed by other type of pesticides.

(C) Gradually increasing the quantities of pesticides used
INCORRECT: Argument already talks about sustained massive use which is not having effect on pesticide resistant insects.

(D) Leaving a few fields fallow every year
INCORRECT: It will not change the reasons which are causing the problem.

(E) Breeding higher-yielding varieties of crop plants
INCORRECT: higher yielding plants can still get affected by insects.

goaltop30mba · Answer

Are pesticides and insecticides the same?

Posted from my mobile device

egmat · Answer

What the passage tells us.

Pesticides are used by farmers.
Continued and massive use of these pesticides lead to two very harmful side-effects
First, the usage often (most of the time) kills the natural enemies of these pests
(Here we can understand why this side-effect is harmful. If the natural enemies of the pests are also killed, then a natural way of getting rid of pests is eliminated leading to the abounding of the pests.)
Second, the usage often and without really intending to do so, leads to the growth of insecticide-resistant pests.
This happens because the insects that are not killed by a particular (not all but only one) insecticide (we can infer here that the insecticide does not always kill all the pests) are the ones that were able to resist is most.
And it is these insecticide-resistant pests that are left alive to breed more such insecticide-resistant pests,
(we can infer here that in future when the same {the same particular one used before} insecticide is again used {sustained and massive use}, then it is ineffective as now it is being used on insects that are resistant to it.)

What we need to do

Question Stem -  From the passage above, it can be properly inferred that the effectiveness of the sustained massive use of pesticides can be extended by doing which of the following, assuming that each is a realistic possibility?
 
Let us suppose that each of the options presents a practical possibility. In that case, based on the information given in the passage, which of these can be used to increase the effectiveness of continuous and massive use of pesticides.

Choice B

Understand the choice
 
The choice says that no one type of insecticide should be used continuously. Rather the type of insecticide used should be changed at regular periods.

Analyze in the context of the passage and the question stem
 
One of the causes of the harmful side effects of pesticides given in the passage is its sustained use. That is, using the same pesticide continuously. The harmful effect is that when a particular (not all but a specific one) insecticide is used, it give rise to insects that are resistant to that particular (that same specific one) insecticide. This happens when the insects that are not killed by that particular insecticide (because they must have been the ones that were able to most resist that particular insecticide) remain alive to breed more of the same insecticide-resistant breed. Now, when the same insecticide is used again (sustained use), then the insects that are now resistant to that particular insecticide cannot be killed.

The above choice offers a logical solution to this part of the cause. If we do not use the same insecticide again then the new insecticide will now act upon the insects that are resistant to the previous insecticide but not to this new one. In this manner, it will be possible to continue to use insecticides without leading to growth of insecticide -resistant insects and also killing the existing ones.

Hence, this choice offers a practical solution to the given problem in the passage

egmat · Answer

Pesticides are chemicals that may be used to kill fungus, bacteria, insects, plant diseases, snails, slugs, or weeds among others. ... Insecticides are a type of pesticide that is used to specifically target and kill insects. Some insecticides include snail bait, ant killer, and wasp killer.

jabhatta2 · Answer

GMATNinja   nightblade354  - while I understand why B is the OA, I do want to clarify something regarding the OA

Would you agree, option B only refers to the 2nd pernicious point mentioned in the red.

Option B doesn't seem to be referring to the 1st pernicious point highlighted in blue ?

I was ideally hoping for a OA that "HITS" both pernicious points mentioned (in the red and in the blue)

Just curious on your thoughts

Thank you

GMATNinja · Answer

It’s definitely true that (B) helps reduce the likelihood of creating insecticide-resistant pests, and (B) may or may not limit the first pernicious effect. The important thing is that it really doesn’t matter.

The question doesn’t ask for an answer choice that limits both pernicious effects. It merely asks for an answer choice that will extend the effectiveness of the sustained massive use of pesticides.

So the most valuable takeaway from this question is really not whether (B) limits the first effect. It’s more that we need to be careful not to pre-think and try to come up with what we feel the right answer should do, without looking at the answer choices. This is particularly relevant because we’re asked to find the BEST answer choice and NOT the right answer choice.

I hope that helps!

niyatisuri · Answer

GMATNinja

Can you please help me understand the impact of option D.
In my opinion, if the a few fields are left fallow, pesticides won't be used because there are no crops. And since the pesticide usage gets a break, wouldn't such a scheme reduce the pesticide resistance?

Regards,
Niyati

GMATNinja · Answer

We're asked to find out how to extend the effectiveness of " sustained  massive use of pesticides."

In other words, how can we use these pesticides  continuously  for a longer period of time?

You're right that (D) would potentially reduce pesticide resistance, but as you've noted, it would require a break in using the pesticides. So, (D) doesn't give us a way to extend the effectiveness of the  sustained  use of pesticides.

Eliminate (D).

I hope that helps!

KarishmaB · Answer

Premises:

The sustained massive use of pesticides in farming has two effects bad effects:
it often kills off the pests' natural enemies in the area.
it  gives rise to insecticide-resistant pests, since those insects that survive a particular insecticide will be the ones most resistant to it, and they are the ones left to breed.

From this we can infer that the  effectiveness  of the sustained massive use of pesticides can be extended by doing which of the following?

Why is the effectiveness lost? Because it leads to insecticide-resistant pests. The insects that survive a  particular insecticide  will be the ones most resistant to it and they will breed creating  more insects of their kind (resistant to the particular pesticide)

So what can we do?

(A) Using only chemically stable insecticides

Irrelevant

(B) Periodically switching the type of insecticide used

Correct. Because insects survive a particular insecticide. If we switch, they may not be able to survive the new one.

(C) Gradually increasing the quantities of pesticides used

If pests are insecticide-resistant, their tolerance will likely keep increasing too. Hence this may not be effective.

(D) Leaving a few fields fallow every year

Irrelevant. No such discussion.

(E) Breeding higher-yielding varieties of crop plants

Irrelevant. No such discussion.

Answer (B)

manrasingh · Answer

Hi  GMATNinja

The questions asks for “sustained” use of pesticides. If we leave a few fields fallow, we won’t need pesticides for these fields. However, we would be using pesticides in the other fields. Overall the use of pesticides can still be sustained. We need a different thinking in my opinion.

This is what I thought of,
1. Will leaving a few fields fallow help in not killing the natural enemies?

This is what I thought of,
1. Will leaving a few fields fallow help in not killing the natural enemies?

Um not sure if leaving a few fields fallow would not kill   the natural enemies. Maybe just leaving a “few” fields fallow is not enough.

2 . Will leaving a few fields fallow help in not making insecticide resistant varieties of pests?

Not sure. Maybe leaving a “few” fields fallow is not enough.

VerbalBot · Answer

Hello from the GMAT Club VerbalBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.

The sustained massive use of pesticides in farming has two effects tha

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Critical Reasoning (CR) Questions

The sustained massive use of pesticides in farming has two effects tha

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards