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schizophrenia...

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by jitendra_mulchandani » Sat Apr 24, 2010 6:20 am
The brains of identical twins are genetically identical. When only one of a pair of identical twins is a schizophrenic, certain areas of the affected twin's brain are smaller than corresponding areas in the brain of the unaffected twin. No such differences are found when neither twin is schizophrenic. Therefore, this discovery provides definitive evidence that schizophrenia is caused by damage to the physical structure of the brain.

If the statements on which the conclusion above is based are all true, each of the following could be true EXCEPT:

(A) People who lack a genetic susceptibility for the disease will not develop schizophrenia.
(B) Medications can control most of the symptoms of schizophrenia in most patients but will never be able to cure it.
(C) The brains of schizophrenics share many of the characteristics found in those of people without the disorder.
(D) It will eventually be possible to determine whether or not someone will develop schizophrenia on the basis of genetic information alone.
(E) Brain abnormalities associated with schizophrenia are the result of childhood viral infections that inhibit the development of brain cells.
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Source: — Critical Reasoning |

by iamseer » Sat Apr 24, 2010 6:48 am
IMO B

must admit it got my head spinning for a while and took me more than 2 minutes. Then tried to find the odd man out.
E is true - inhibit development of brain cells resulting in smaller size
D is possible - b'cos studying genetic info of those with disease might help find the reason
C is true again - argument says only a certain portion of brain is smaller
A is true again - b'cos the disease seems to be caused by physical damage==genetic damage

I guess I was taken for a ride b'cos to me genetically identically is different from structural identical. But if we take both of them to same then the argument seems less confusing and odd man amongst answer options stands out.

One another way could be just to look for the extreme "will never be able to cure it" - too extreme

Anyone got a better way to do this faster? or perhaps more efficiently?
"Choose to chance the rapids and dance the tides"
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by jitendra_mulchandani » Sat Apr 24, 2010 7:39 am
@iamseer : Get ready for some more spin, since the OA is D

I too picked up B...:(

Please find below my reasoning for OA


If the statements on which the conclusion above is based are all true, each of the following could be true EXCEPT:

(A) People who lack a genetic susceptibility for the disease will not develop schizophrenia.
--This can be true since schizophrenia is genetic/physical damage

(B) Medications can control most of the symptoms of schizophrenia in most patients but will never be able to cure it.
--Only thing which can eliminate this Answer choice is that schizophrenia is caused by physical damage,hence it will be impossible to cure it.

(C) The brains of schizophrenics share many of the characteristics found in those of people without the disorder.
This is stated in the argument..."Certain areas of the affected twin's brain are smaller than corresponding areas in the brain of the unaffected twin"

(D) It will eventually be possible to determine whether or not someone will develop schizophrenia on the basis of genetic information alone.
--The argument states the pysical damage as a evidence but does not mention that it will be possible to determine the diesease.

(E) Brain abnormalities associated with schizophrenia are the result of childhood viral infections that inhibit the development of brain cells.
---Can be true, since the affected twin's brain is smaller.
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by tpr-becky » Sat Apr 24, 2010 4:21 pm
I say D becuase if schizophrenia is due to physical damage to the brain then it won't ever be possible to genetically predict it because physical damage happens after you get your genetics.
Becky
Master GMAT Instructor
The Princeton Review
Irvine, CA
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by kaushals » Mon Apr 26, 2010 2:02 am
@ tpr-becky
If i consider the above reasoning then A also cant be true because not being genitically susceptible doesn't imply that i cant have any future physical damage .
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by liferocks » Mon Apr 26, 2010 3:28 am
jitendra_mulchandani wrote:The brains of identical twins are genetically identical. When only one of a pair of identical twins is a schizophrenic, certain areas of the affected twin's brain are smaller than corresponding areas in the brain of the unaffected twin. No such differences are found when neither twin is schizophrenic. Therefore, this discovery provides definitive evidence that schizophrenia is caused by damage to the physical structure of the brain.

If the statements on which the conclusion above is based are all true, each of the following could be true EXCEPT:

(A) People who lack a genetic susceptibility for the disease will not develop schizophrenia.
(B) Medications can control most of the symptoms of schizophrenia in most patients but will never be able to cure it.
(C) The brains of schizophrenics share many of the characteristics found in those of people without the disorder.
(D) It will eventually be possible to determine whether or not someone will develop schizophrenia on the basis of genetic information alone.
(E) Brain abnormalities associated with schizophrenia are the result of childhood viral infections that inhibit the development of brain cells.
I will go with D.

Premise says "The brains of identical twins are genetically identical but physically different When only one of a pair of identical twins is a schizophrenic"
So only from genetic information one cannot conclude whether the person is schizophrenic. D clearly says the opposite.hence ans is D.
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by iamseer » Mon Apr 26, 2010 11:02 am
tpr-becky wrote:I say D becuase if schizophrenia is due to physical damage to the brain then it won't ever be possible to genetically predict it because physical damage happens after you get your genetics.
vow!!
ok so between B and D, why is D the winner?

as in how do we kill B?
"Choose to chance the rapids and dance the tides"
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by tpr-becky » Mon Apr 26, 2010 2:48 pm
remeber you are looking for which one must be false.

A) it could be true that people who lack a genetic susceptibililtiy will not develop it - it also could be true that the will develop it. A doesn't really say much if it is not genetic.

B. It could be true that medications can control the symptoms but won't be able to cure it - they don't tell us anything that would rule medications out, so that could be true.

D) It can never be true that it will be possible to determine Schizophenia with genetics alone because, as the argument states, schizophrena is caused by physical damage, not genetics.
Becky
Master GMAT Instructor
The Princeton Review
Irvine, CA
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