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Mice poison

Expert replies
by ssgmatter » Tue May 11, 2010 7:30 am
Mice that have been given morphine are very likely to develop blood poisoning because
bacteria that normally reside in the intestine typically respond to morphine by
migrating into the bloodstream. However, when mice are given both morphine and the
new drug naltrexone, blood poisoning is much less frequent, although it does still
occur. These results provide support for researchers’ prediction that naltrexone will
turn out to be toxic to certain types of bacteria.
Which of the following, if discovered to be true, would most seriously weaken the
support for the researchers’ prediction?
A. After being administered to mice, naltrexone does not pass from the
bloodstream into the intestine.
B. Naltrexone inhibits morphine from triggering the migration of intestinal bacteria
into the bloodstream.
C. Mice that have been given naltrexone but not morphine have no greater risk of
developing blood poisoning than do mice that have not been given either
substance.
D. The increased risk of blood poisoning is not the only harmful effect on mice of
being given morphine.
E. Conditions other than the presence of intestinal bacteria in the bloodstream can
cause blood poisoning in mice.

Any thoughts guys?

C makes invalid comparison here....so not the correct one

D irrelevant to the conclusion

E other conditions out of scope

A who cares if naltrexone not pass from blood to interstine..

B left out with this one only

However can anyone explain why B is the correct or the wrong option here...

Many thanks!
Best-
Amit
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Source: — Critical Reasoning |

by sakali » Tue May 11, 2010 7:50 am
"B" would support the conclusion...not weaken it. If the drug works as the researcher claims it does...what's the problem?


To me, "E" seems plausible. If there are other causes for blood poisoning, then the Researcher's finding, that the new drug causes less frequent blood poisoning by attacking the bacteria, can be questioned.

Do you have the OA?
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by kstv » Tue May 11, 2010 7:53 am
Morphine induces intestinal bacteria to get which leads to blood poisoning. When Naltrexone is also adminstered the poisoning reduces. Conclusion Naltre... kills the intestinal bacteria directly.

A) If Naltre.... does not pass it strengthens the conclusion. It kills the bacteria before it migrates.

B) Morphine triggers migration , if Naltre does the opp then is reduces blood poisoning without being directly detrimental to the bacteria. This weakens the conclusion of the argument.

C) Just Naltre should reduce the risk if it directly kills the bacteria, but on its own it is neutral to intestinal bacteria. This is a bit tricky.
In a way this is a weakener also but B gives a better reason how Naltre reduces blood poisoning indirectly.
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by kevincanspain » Tue May 11, 2010 8:08 am
sakali wrote:"B" would support the conclusion...not weaken it. If the drug works as the researcher claims it does...what's the problem?


To me, "E" seems plausible. If there are other causes for blood poisoning, then the Researcher's finding, that the new drug causes less frequent blood poisoning by attacking the bacteria, can be questioned.

Do you have the OA?
Note that their hypothesis is that the drug is toxic the bacteria. How could blood poisoning be less frequent if the drug doesn't kill the bacteria? If B is true, the bacteria, in response to the drug, never gets into the bloodstream and thus never causes blood poisoning
Kevin Armstrong
GMAT Instructor
Gmatclasses
Madrid
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by sakali » Tue May 11, 2010 8:17 am
Thanks for the clear explanations guys.

I get it now :)
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