Q7 - Scientist: In our study, chemical R

[ohthatpatrick]

Question Type:
Determine the Function

Stimulus Breakdown:
Conclusion: Just because R didn't cause cancer in rats doesn't mean that R is safe for humans.
Evidence: Lots of stuff that we know is carcinogenic to humans didn't cause cancer in rats, probably because rats don't live long enough to manifest the carcinogenic effects.

Answer Anticipation:
Well, it's outside the conclusion and the premise. So it's Something Else. The fact that it's followed by "but" is a pretty solid indicator that it's a counterpoint to what the author is arguing. The fact that R didn't cause cancer in rats would support the idea that "R is safe for humans". Our author is saying, "it does not PROVE that R is safe for humans, since other factors need to be considered." So it is a background fact that sounds encouraging about R. But the author's goal in this argument is to keep people from being overly enthusiastic about R's safety. The author accepts the first sentence, but is trying to make sure people don't jump to a hasty conclusion on the basis of it.

Correct Answer:
C

Answer Choice Analysis:
(A) It is not used to support a conclusion, so it's not evidence.

(B) It is not used to support a conclusion.

(C) It is not used in order to illustrate a claim. It is just the factual starting point for the author's discussion. The author Is presenting this fact and arguing "don't overreact to it."

(D) It is not used to support a conclusion.

(E) Yes! The author's conclusion is literally saying "this first sentence is insufficient to conclude that R is safe for humans". She then supports that conclusion with the evidence that follows "after all".

Takeaway/Pattern: It's very typical for arguments on Main Conclusion and Determine the Function to have "upside down" arguments, in which you get the Conclusion before you get the Premise. It's also very common for those Conclusions to have a but/yet/however Rebuttal feel to them. "After all" always indicates that you're about to hear a premise and that you just heard a conclusion.

#officialexplanation

[yoohoo081]

Could somebody explain why E is the role that fit the description that chemical R did not cause cancer in lab rats?

I guessed C, because the statement says rats are short lived. Why is C wrong?

Thank you,

[farhadshekib]

Could somebody explain why E is the role that fit the description that chemical R did not cause cancer in lab rats?

I guessed C, because the statement says rats are short lived. Why is C wrong?

Thank you,

Here's my take on it:

Sentence 1: Chem R did not cause cancer in lab rats.

Conclusion: But we cannot conclude from this that chem R is safe.

Sentence 2: After all, many substances know to be carcinogenic to humans cause no cancer in rats.

Sentence 3: This is probably because some carcinogens cause cacner only via long term exposure and rats are short lived.

The "but" in sentence 2, followed by "after all" in sentence 3, should of alerted you that sentence 2 is the conclusion.

(E) has it right. Sentence 1 is a claim presented by the author, so that he can set up his conclusion - that is, the study doesn't prove that Chem R is safe for humans.

So sentence 1 is taken as insufficient to support the notion that chem R is safe for humans.

(C) is a premise that the author uses to support his conclusion, rather than being illustrated by sentence 1.

[noah]

Nice write-up! I've added a bit below on the other wrong answers:

Sentence 1: Chem R did not cause cancer in lab rats.

Conclusion: But we cannot conclude from this that chem R is safe.

Sentence 2: After all, many substances know to be carcinogenic to humans cause no cancer in rats.

Sentence 3: This is probably because some carcinogens cause cacner only via long term exposure and rats are short lived.

The "but" in sentence 2, followed by "after all" in sentence 3, should of alerted you that sentence 2 is the conclusion.

(E) has it right. Sentence 1 is a claim presented by the author, so that he can set up his conclusion - that is, the study doesn't prove that Chem R is safe for humans.

So sentence 1 is taken as insufficient to support the notion that chem R is safe for humans.

(A) is tempting, however the argument doesn't conclude that R is safe - just that we can't conclude it's dangerous.

(B) suggests that the fact that R didn't cause cancer is used to support the idea that we can't use that fact to say anything about humans. That doesn't make sense! The issue of what inter-species extrapolation we can do is used to limit the "impact" of the part in question. The evidence about R isn't used to support the limitation!

(C) suggests that the conclusion is that rats are too short-lived to blah, blah. But we know that that fact is used to support the conclusion that we can't extrapolate.

(D) suggests the conclusion is that R causes cancer. All we know is that we can't say it doesn't from the evidence we have.

[aimes]

Can someone else please explain why "C" is wrong - the reasons posted don't seem to make a lot of sense to me as reason for "C" being false. I can understand how E is the right answer, but it still appears to me like C is also right.