a nice RC Passage

[akasans]

In 1994, a team of scientists led by David McKay began studying the meteorite ALH84001, which had been discovered in Antarctica in 1984.Two years later, the McKay team announced that ALH84001, which scientists generally agree originated on Mars, contained compelling evidence that life once existed on Mars. This evidence includes the discovery of organic molecules in ALH84001, the first ever found in Martian rock. Organic molecules--complex, carbonbased compounds--form the basis for terrestrial life. The organic molecules found in ALH84001 are polycyclic aromatic hydrocarbons, or PAH's. When microbes die, their organic material often decays into PAH's.
Skepticism about the McKay team's claim remains, however. For example, ALH84001 has been on earth for 13,000 years, suggesting to some scientists that its PAH's might have resulted form terrestrial contamination. However, McKay's team has demonstrated that the concentration of PAH's increases as one looks deeper into ALH84001, contrary to what one would expect from terrestrial contamination.The skeptic's strongest argument, however, is that processes unrelated to organic life can easily produce all the evidence found by McKay' steam, including PAH's. For example, star formation produces PAH's. Moreover, PAH's frequently appear in other meteorites, and no one attributes their presence to life processes. Yet McKay's team notes that the particular combination of PAH's in ALH84001 is more similar to the combinations produced by decaying organisms than to those originating form nonbiological processes.
Q1:
The passage asserts which of the following about the claim that ALH84001 originated on Mars?

A. It was initially proposed by the McKay team of scientists.
B. It is not a matter of widespread scientific dispute.
C. It has been questioned by some skeptics of the McKay team's work.
D. It has been undermined by recent work on PAH's.
E. It is incompatible with the face that ALH84001 has been on Earth for 13,000 years.
Q2:
The primary purpose of the passage is to

A. describe new ways of studying the possibility that life once existed on Mars
B. revise a theory regarding the existence of life on Mars in light of new evidence
C. reconcile conflicting viewpoints regarding the possibility that life once existed on Mars
D. evaluate a recently proposed argument concerning the origin of ALH84001
E. describe a controversy concerning the significance of evidence from ALH84001
Q3:
The passage suggests that the fact that ALH84001 has been on earth for 13,000 years has been used by some scientists to support which of the following claims about ALH84001?

A. ALH84001 may not have originated on Mars.
B. ALH84001 contains PAH's that are the result of nonbiological processes.
C. ALH84001 may not have contained PAH's when it landed on Earth.
D. The organic molecules found in ALH84001 are not PAH's.
E. The organic molecules found in ALH84001 could not be the result of terrestrial contamination.

[password]

Q1 : B - as the question relates to the claim that AL84001 is from Mars or not
Q2 : E - Seems straighforward
Q3 : B - as the scientists say "however, is that processes unrelated to organic life can easily produce all the evidence found by McKay' steam"


Correct my answers if they are wrong.

[akasans]

I agree with you for the first question, but in the third one, I think the answer should be C because the passage said that ALH84001 has been on earth for 13,000 years, suggesting to some scientists that its PAH's might have resulted form terrestrial contamination. Please explain me more why you think E is the answer for the second one because I think it should be C.

[password]

For Q2 : The reason I chose E is because the conflict is reagarding how PAH got deposited in the AL84001 and not if PAH is the reason for the life in Mars..

[guggi2]

1.b because the McKay team had some good reasons to gainsay the skeptics.
2.e The skeptics tried to contradict MaKay team's evidence.
3.a ALH84001might have resulted form terrestrial contamination(on the earth). that means ALH84001 may not have originated on Mars.

[gmat168]

The third answer is C. The fact the the fragment is from Mars is not being disputed. What is being disputed is if there is evidence of life (PAH's) from Mars or whether these PAH's were simply a result of contamination from earth.

[batman2004]

For Q1, option D is attractive. But, nowhere in the passage did it suggest that the work of PAH is recent. Any opinion?

[nikki_parekh]

b,e,b wats the oa

[GauravDhamija]

why is b correct for the first answer....??

[crash]

My choices:

1) B - "...scientists generally agree originated on Mars..." means that is this fact is not a matter of widespread dispute

2) E - seems fine. The author is describing a theory. Someone was wondering why it is not B. Well, there is no revision to the theory. Scientists are speculating.

3) C - I originally chose C, but after reading some of the replies to the post some doubt crept in. I was torn between B and C. IMO, the answer is C.
Scientists say that B happens because of Star Formations and this theory is a different from the contamination theory. Because there is a separate explaination for PAH's arising from non-biological sources, we can rule it out.

What are the OA's??

-- I hate questions without OA's in spoilers!!

Akasans - I have seen this passage somewhere. Where did you get it from?