LSAT 77, Reading Comprehension, Q26, LSATHacks

RC Question 26 Explanation, by LSATHacks

QUESTION TEXT: Which one of the following, if true, would…

DISCUSSION: Most of the wrong answers expect you to have misunderstood the process, so it’s worth revising here.

DNA mutation ➞ gets written to RNA ➞ RNA writes mutation back to DNA (i.e. “reverse transcription”) ➞ virus takes DNA from immune cell to reproductive cells

It’s only the fourth step that’s unproven.

___________

1. CORRECT. This is incredibly strong support for Steele’s theory. Paragraph 4 was about whether or not a virus could in fact alter reproductive cells. This answer shows that it is possible.
2. This doesn’t provide any support. We need to know if the mechanism for the theory works. The mechanism is a virus writing RNA information back into DNA.
   The mutations themselves weren’t important. It was whether they could be written back that was important.
3. Who cares? The important bit is the final step in the chain above. Step 1 is the immune system making mutations. That’s proven. How they test the effectiveness of the mutations (i.e. trial and error, or some other method) is irrelevant.
4. This isn’t necessarily Lamarckian. Natural selection could account for neck growth.
5. This isn’t necessarily the same thing as passing on DNA. It could be a vaccine-like process or some other non-genetic mechanism that passes on the immunity.

Hi, I'm Graeme Blake

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