It is proposed to introduce mosquitoes into the wild with geneti

Question

It is proposed to introduce mosquitoes into the wild with genetic alterations that destroy their disease-carrying capacity. In this way, the dangerous wild population could eventually be replaced with a harmless one without leaving room for another disease-transmitting type to flourish. One candidate gene would interfere with the mosquito’s finding mates; another would cause destruction of a disease parasite before the stage at which it could be transmitted; another would disable the mosquito’s own resistance to disease, so that it would die before transmitting the disease.

Which of the following identifies a discrepancy in the proposal above?

A.It is presupposed that the three genes would prove equally easy to isolate and insert into the cells of the mosquitoes.
 
B.Two of the ways of destroying disease carrying capacity in the wild would jeopardize the goal of the proposal.

C.It does not take into account positive roles that mosquitoes play in the environment, such as serving, in the larval stage, as food for fish.
 
D. None of the proposed alternatives would ensure that there would be fewer mosquitoes in any given area.
 
E. Evidence is not presented to show that each alternative method has been successfully tested on a wide scale.

Nevernevergiveup · Accepted Answer

It is proposed to introduce mosquitoes into the wild with genetic alterations that destroy their disease-carrying capacity. In this way, the dangerous wild population could eventually be replaced with a harmless one without leaving room for another disease-transmitting type to flourish. One candidate gene would interfere with the mosquito’s finding mates; another would cause destruction of a disease parasite before the stage at which it could be transmitted; another would disable the mosquito’s own resistance to disease, so that it would die before transmitting the disease.

Which of the following identifies a discrepancy in the proposal above?

A. It is presupposed that the three genes would prove equally easy to isolate and insert into the cells of the mosquitoes.
B. Two of the ways of destroying disease carrying capacity in the wild would jeopardize the goal of the proposal.
C. It does not take into account positive roles that mosquitoes play in the environment, such as serving, in the larval stage, as food for fish.
D. None of the proposed alternatives would ensure that there would be fewer mosquitoes in any given area.
E. Evidence is not presented to show that each alternative method has been successfully tested on a wide scale.

chetan2u · Answer

HI,
I will straight talk of the role of three genes..
1) 1 is unambiguous about the role- it will not allow the population to increase by decreasing the mating between the wild mosquitos.
2) 2 will increase the immunity within the mosquito to fight the parasite so that the parasite spreading disease to humans via mosquito is killed by mosquito before it can spread the disease.
3) 3rd will decrease the resistance power of the mosquitos wherein the mosquitos instead of just spreading it get affected themselves and get killed by the parasite..

so if you look at it, in a way the 2nd gene is increasing the immunity and 3rd is decreasing the immunity of the mosquito. they are working in opposite directions

Carcass · Answer

Please:  whenever post a question be really careful.

A CR without the stem is like a car without the steering wheel.

Thank you for your collaboration

PiyushK · Answer

B it is.

Last 2 genes are conflicting. 
another would cause destruction of a disease parasite before the stage at which it could be transmitted; another would disable the mosquito’s own resistance to disease, so that it would die before transmitting the disease.

nirav2610 · Answer

"Two of the ways ..."(not mating & dying) Does this mean the 2nd gene would not jeopardize the goal of the proposal?

sun01 · Answer

"another would cause destruction of a disease parasite before the stage at which it could be transmitted; another would disable the mosquito’s own resistance to disease, so that it would die before transmitting the disease."

These two ways are contradicting each other.

So, it should be B.

These two ways are contradicting each other.

So, it should be B.

hwgmat2015 · Answer

Objective here is to replace harmful mosquitoes will harmless ones.

option A - Out of Scope
Option B- Yes. The two options contradict the main objective. 
Option C- Out of Scope
Option D- Fewer mosquitoes . Not relevant with the objective.
Option E- Out of Scope.

Answer: B

PrakharGMAT · Answer

Hi Experts /  chetan2u  ,

I am not able to understand this argument. Can you please help.

PiyushK ,
Can you please suggest how Last 2 genes are conflicting...?

In-fact I think the last 2 genes are similar, Second gene is causing destruction in disease parasite so that the disease can't be transferred and other is killing the mosquito so that the disease can't be transferred.

Actually, I am not able to comprehend this argument what it is trying to say.

Please assist.
Thanks and Regards,
Prakhar

arirux92 · Answer

Hi Prakhar,

the question is basically this : creating a breed of mosquito with the following characteristics :

1) One candidate gene would interfere with the mosquito’s finding mates
2) Another would cause destruction of a disease parasite before the stage at which it could be transmitted
3) another would disable the mosquito’s own resistance to disease, so that it would die before transmitting the disease.

So the assumption is that that particular breed of mosquito will breed with mosquitoes in the wild and produce offsprings with those characteristics and so on... resulting in reducing the parasite which kills the diseases.

But if you look closely at 1 and 3

1)One candidate gene would interfere with the mosquito’s finding mates

This means the mosquito will not be able to breed. Destroying the assumption

3) another would disable the mosquito’s own resistance to disease, so that it would die before transmitting the disease.

Which means the mosquito is highly vulnerable to that disease. So as soon as it goes into the wild, it dies and shall no longer be able to breed or fulfill the assumption in the first place

These two points cancel assumption

As for 2) It's saying it will destroy the parasite before it is transmitted; not the mosquito. While 3 says that the mosquito will die. They are not the same at all 2 is killing the disease, 3 is killing the messenger

PrakharGMAT · Answer

Hi Folks /  chetan2u ,

Thanks for your contribution and helping me to understand the argument.
I just want to reiterate the situation so that you can confirm I understood it correctly-

The are 2 entities-
1. Parasite
2. Mosquito
3. Human

Parasite enters in the mosquito to find mate
Mosquito gets the disease.
So, when Mosquito attack to human, Human gets the disease.

Talking about last 2 genes-

-->another would cause destruction of a disease parasite before the stage at which it could be transmitted; 
This says, the gene will destruct PARASITE before it could transmit to MOSQUITO.

-->another would disable the mosquito’s own resistance to disease, so that it would die before transmitting the disease.
This says, the gene will destruct MOSQUITO's resistance to PARASITE before it could transmit disease to HUMAN.

Am I thinking in right direction..??

Thanks and Regards,,
Prakahr

chetan2u · Answer

Hi,
the beginning of whole thing could be--
1) The wild mosquitos are susceptible to these parasite, which cause disease. So, they get this parasite from some other diseased person or animal when they bite that person or animal, and they just become carrier/transmitter of it. The moment they bite some healthy person, they transmit the disease to him/her but in the process they do not get affected because of immunity in their body against these parasite.
2) Now what is the role of these genes..
a) 1st will make changes in their body such that they find it difficult to find a partner to mate. this will effect their population. slowly this NEW breed will replace the existing parasite carrying breed.
2) 2nd will produce changes such that they kill the parasite before it becomes powerful enough to get transmitted.
3) 3rd stage will weaken the resistance power of these mosquitos so that they themselves die of it rather than transmit..

Now the TWO discrepancies--
1) On one hand we are making changes 2 and 3 so that this new breed kills the parasite and slowly replaces the existing breed, BUT simultaneously the 1st gene is making it difficult to find partner to mate, finally this will effect this new breed too and their gene will not allow them to find partner, which we want to replace with.
2) 2nd and 3rd are almost doing the opposite thing - In a way one is increasing the immunity and the OTHER is destroying it..

chesstitans · Answer

the source of this question is from veritas prep. 
Such question will be modified in the actually gmat, I believe so.

B is a common pattern, but in this question, it is hard to recognize the pattern in B.
B is indeed the correct b/c if mosquitoes cannot find mates, or die by its own disease, then mosquitoes will not serve the goal that "the dangerous wild population could eventually be replaced with a harmless one without leaving room for another disease-transmitting type to flourish."

balaji4799 · Answer

I didn’t understand option B completely, it says two of the options however only one of the candidate gene is killing the carrier( the third one ) where as the other two seems benine to the mosquito

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mini246 · Answer

One candidate gene would interfere with the mosquito’s finding mates; another would cause destruction of a disease parasite before the stage at which it could be transmitted; another would disable the mosquito’s own resistance to disease, so that it would die before transmitting the disease.

Which of the following identifies a discrepancy in the proposal above

If the mosquito is unable to find a date that means the gene in the mosquito will not pass on to the general population.hence defeats the purpose since the harmful population of mosquitoes won't be replaced. For second discrepancy assume that it is in the final adult stage that the disease develops in the mosquito now either the mosquito dies or the parasite . Again no change in the existing harmful population

Hence B

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AkshdeepS · Answer

Which of the following identifies a discrepancy in the proposal above?

A. It is presupposed that the three genes would   prove equally easy to isolate and insert   into the cells of the mosquitoes.

B.   Two of the ways of destroying disease carrying capacity in the wild would jeopardize the goal of the proposal.

C.   It does not take into account positive roles   that mosquitoes play in the environment, such as serving, in the larval stage, as food for fish.

D. None of the proposed alternatives would ensure that there would be   fewer mosquitoes in any given area.

E.   Evidence is not presented to show   that each alternative method has been successfully tested on a wide scale.

A. Ease or difficulty to isolate or insert is not the concern. Even if the plan is successful with difficulties then it is good.

B. It shows the clear reason that if two ways would jeopardize the plan then plan is almost fails. Plan is to introduce harmless

mosquitoes, but as the premise says  "another would disable the mosquito’s own resistance to disease, so that it would die before

transmitting the disease" , this will jeopardize the proposal.

C, D, and E are Irrelevant to the discrepancy.

push12345 · Answer

Our main intent is not to decrease population of mosquitoes but simply replacing them with harmless ones

1st and 3rd reason will decrease population of mosquitoes
1) If the mosquito is unable to find a date that means the gene in the mosquito will not pass on to the general population.hence defeats the purpose since the harmful population of mosquitoes won't be replaced

3)another would disable the mosquito’s own resistance to disease, so that it would die before transmitting the disease

So mosquitoes will die in this case too

Give kudos if it helps

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rvgmat12 · Answer

VeritasKarishma   GMATNinja  could you please provide your inputs on this?

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KarishmaB · Answer

Aim: destroy mosquitoes' disease-carrying capacity

Plan: Introduce mosquitoes with 3 possible genetic alterations:

- One candidate gene would interfere with the mosquito’s finding mates; 
- another would cause destruction of a disease parasite before the stage at which it could be transmitted; 
- another would disable the mosquito’s own resistance to disease, so that it would die before transmitting the disease.

What is the problem with the plan?

A.It is presupposed that the three genes would prove equally easy to isolate and insert into the cells of the mosquitoes.

Does the plan need them to be equally easy to isolate? No. They are just possible options. One could be easier to implement and the other harder (but perhaps better) - we don't know. 
 
B.Two of the ways of destroying disease carrying capacity in the wild would jeopardize the goal of the proposal.

Correct. 
We plan to introduce modified mosquitoes and we hope that they will replace the current ones. So they will propagate among the current ones and perhaps pass on their genes to the babies (new mosquitoes) and eventually, when current mosquitoes live out their life cycle, all mosquitoes will have the new genes. 
But of the 3 proposals,
- One candidate gene would interfere with the mosquito’s finding mates; 
If the introduced mosquitoes are unable to find mates, how will they replace the current population? The current population will continue mating among themselves and propagating.

- another would cause destruction of a disease parasite before the stage at which it could be transmitted; 
This is good. The mosquito would kill the parasite before transmitting so the mosquito will become harmless.

- another would disable the mosquito’s own resistance to disease, so that it would die before transmitting the disease.
This again would lead to the introduced mosquitoes being weak and not resistant to disease. So they will die quickly and not be able to propagate. Then how will they replace the current population?

Hence, 2 of the 3 ways are against our goal.

C.It does not take into account positive roles that mosquitoes play in the environment, such as serving, in the larval stage, as food for fish.
 
Irrelevant.

D. None of the proposed alternatives would ensure that there would be fewer mosquitoes in any given area.
 
Irrelevant. We only want to make mosquitoes harmless.

E. Evidence is not presented to show that each alternative method has been successfully tested on a wide scale.

Evidence if out of scope for us.

Answer (B)

VerbalBot · Answer

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It is proposed to introduce mosquitoes into the wild with geneti

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