Q18

[skapur777]

I got this one correct but why couldn't E just as easily be correct?

[ManhattanPrepLSAT1]

Good question! And thanks for bringing this to the forum.

We know from the passage that some genes can be transmitted horizontally. But this question is asking about the absence of cell walls in some bacteria. In lines 19-22 the passages states that the absence of cell walls "results from changes in the interactions among genes, without any attendant changes in the genes themselves."

That doesn't sound like the absence of cell walls is something that can be transmitted horizontally, since the absence of the cell wall is not actually a gene. This eliminates answer choice (E).

(A) is contradicted. It's the interactions among genes, not a gene itself.
(B) is unsupported by the passage.
(C) can be inferred from lines 15-22.
(D) is unsupported by the passage.
(E) is unsupported by the passage. (Hint: this answer relates information from paragraph 4. Be careful about answer choices that link information from such great distances in the passage)

Hope that helps! Let me know if you have any further questions on this one.

[skapur777]

Wow, thank you! Can't believe I didn't pick up on that, I feel just as guilty getting questions correct for the wrong reasons haha

[csunnerberg13]

Sorry I'm not understanding why lines 19-22 should point me away from E. The science language endlessly trips me up on the LSAT, but to me (i.e. the non-science savvy reader) - lines 19 to 22 basically says "the absence of the cell walls results from changing the genes interaction with each other, not from changing the gene itself." Also - horizontally basically just means the environment, rather than the inherited gene structure, causes the change. I'm not sure why what lines 19-22 describes wouldn't be considered an environmental change when it is explicitly telling me that it wasn't caused by the gene alteration...

Also, just before someone points this out - I know it says "This inherited absence of cell walls " -- but in this context, it still doesn't sound like they've "inherited" something in the traditional sense - it sounds more like a consequence of the environmental change that was then passed on.

[einuoa]

The reason that E is unsupported in the passage is that, the bacterium is growing and multiplying indefinitely without walls, and it's an inheritance of acquired characteristics. But, in this case, the bacteria is only one bacteria, to make the example a little clearer, pretend that the bacteria is a person.

So, the experiment removes the gene of liking ice cream in a person (bacteria), the person's gene continues growing, and that person dislikes ice cream more and more until she absolutely cannot tolerate even the smell of it. This gene is so strong that it's passed down to her kids, so all of her kids can't tolerate ice cream. To transmit horizontally to other people (bacteria), we don't know if it's possible or not, maybe this gene is infectious and so she can transmit it, but what if it's not? We simply can't infer. This is why C is correct.