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.

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.
_________________

Piyush K
-----------------------
Our greatest weakness lies in giving up. The most certain way to succeed is to try just one more time. ― Thomas A. Edison
Don't forget to press--> Kudos
My Articles: 1. WOULD: when to use? | 2. All GMATPrep RCs (New)
Tip: Before exam a week earlier don't forget to exhaust all gmatprep problems specially for "sentence correction".

"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.

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
_________________

Thanks and Regards,
Prakhar

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
_________________

Kudos if I helped

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..
_________________

1) Absolute modulus : http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html
3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html


GMAT online Tutor

[quote="Nevernevergiveup"]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.[/quote]

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

[size=80][b][i]Posted from my mobile device[/i][/b][/size]

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.
_________________

"Do not watch clock; Do what it does. KEEP GOING."