#22 - Must Be True

[Administrator]

Complete Question Explanation
(See the complete passage discussion here: lsat/viewtopic.php?t=14217)

The correct answer choice is (B)

This choice requires a specific piece of information: the author’s explanation, presented beginning
on line 41, for why native species of plants grew better when growing naturally on nearby land then
when growing in plots enriched from soil nearby. Researchers, the author provides, concluded that
this was attributable to the fact that overfarmed lands are overrun with aggressive disease organisms
while lacking beneficial microorganisms.

Answer choice (A): The issue is not a lack in key nutrients, so this choice can be eliminated from
contention.

Answer choice (B): This is the correct answer choice. As discussed, the researchers concluded that
such land is usually overrun with aggressive disease organisms.

Answer choice (C): Overfertilization is not the issue that is presented to explain the results specified
in the question.

Answer choice (D): This clever choice was popular among test takers; overfarmed land is overrun
with disease and lacking beneficial microorganisms. The soil that was taken from the out-ofproduction
land may have had some such microorganisms, although the plots to which the soil was
taken may have been lacking.

Answer choice (E): The harmful organisms were concluded to be present in the overfarmed land, not
in the land that had been taken out of production.

[Rita]

Could you please explain why B is a better answer than A? Looking at that portion of the passage, the researchers concluded that the problem is twofold (45) - fields farmed for many years are overrun with aggressive disease organisms (B), and beneficial mycorrhiza are lacking (A?). Is the idea just that these beneficial fungi are organisms, not nutrients?

Thanks,
Rita

[Clay Cooper]

Hi Rita,

Thanks for your question. You are correct - answer choice A is wrong because beneficial microorganisms like fungi are not nutrients. That leaves B, which names precisely one of the two reasons the plants fared better that we are given in (45).

I hope that helps!

[Rita]

Yes that does, thanks Clay!

[Edmund]

I hate to be this guy, but I'm really confused by this question and the closer I look, the more the question itself seems to misrepresent the passage.

The question asks ". . . why native plant varieties grew better when sown on land that had been out of production for 20 years than when sown on the plots enriched with soil taken from that land?"

But the beginning of paragraph three says that "on some of the plots [described in the previous paragraph only as "a former cornfield"--no mention of how long this land had been out of production] sown with seeds of native plant species, soil from nearby land had been taken out of production 20 years earlier was scattered to see what effect introducing . . . other beneficial microorganisms . . . might have on the process of native plant repopulation."

So right off, there seems a discrepancy; the passage never says anything was sown on land that had been out of production for 20 years, but rather that soil from such land was scattered onto the test plots.

I could write this off, but it seems to really scramble the whole question, because as the third paragraph continues, it contrasts the positive effect this 20-year-old transplanted soil has on the test plots with the success of plants growing on nearby land that had never been farmed: "The seeds sown on these enriched plots have fared better than the seeds sown on the unenriched plots, but still not as well as those growing naturally on the nearby land." It then goes even further, and explains this deficiency in the transplanted soil by saying "Researchers have concluded that this is because fields farmed for many years are overrun with aggressive disease organisms, while . . . beneficial mycorrhiza . . . are lacking."

Now, there is an ambiguity as to whether "fields farmed for many years" refers to the test plot itself or the 20-year-out-of-production land from which soil has been transplanted, but given that this information is presented to explain why the test-plots-with-transplanted-soil don't do as well as the never-farmed land, it's at least as plausible that it refers to the transplanted soil or the transplanted soil and the test plots as to the test plots only, which would make E at least as good an answer as B.

I don't know. I can see how B is as good but I don't know how to distinguish between them in this case.

[Zach Foreman]

Edmund,
I do agree that the wording at a few key points of the passage could have been more precise. Specifically, the passage should have specified how long ago the test plot had been planted with corn. We can infer that it was likely less than a year, since the whole purpose of the study is to see what happens to land after production ceases. Further, they say that changes occurred after three years. If it had been, say, 5 years since last corn planting, this wouldn't make much sense.
Another specific change would be in line 44, "but still not as well as those growing naturally on the nearby land." I interpret that as being the same "nearby land" as mentioned in line 36, the 20 year fallow land that they got soil from.
This interpretation is confirmed by the question stem. There are 3 plots of land (with varying things sown on it that we will ignore for now):A. land recently used to grow corn, B. land that had grown corn 20 years earlier and C. land recently used to grow corn amended with soil from the land that had grown corn 20 years earlier.
So, the question stem is asking us to compare the performance of plants on lands B and C. You are correct, nothing was sown on B land but they did compare the grasses and plants on that natural land with the plants on C and saw a difference. The question is asking us to explain that difference.
And finally, yes, all three types of land fall under the category of being "farmed for many years".
The basic idea is that if there are multiple interpretations, choose the one that yields one and only one correct answer. E doesn't work because it is an opposite answer. It is not land B that has the bad microorganisms, but C. Yes it had some good ones from the amended soil but it was still diseased.

[Edmund]

OK, that helps. Thank you!

[ashpine17]

I am still confused about answer choices B and D. As for B, is the support from lines 45-50? As for D, why is it incorrect? Doesn't it say in the same paragraph that beneficial fungi are lacking?

[sbhumra@ryerson.ca]

I am still confused about answer choices B and D. As for B, is the support from lines 45-50? As for D, why is it incorrect? Doesn't it say in the same paragraph that beneficial fungi are lacking?

Hi Powerscore,

I was wondering the same as Ashpine that what is the difference between B and D where the field was overrun with harmful and aggressive organisms because they were lacking the fungi and other beneficial organisms. What sets them apart?

Thank you

- Sahiba

[Adam Tyson]

If the soil taken from the nearby land was lacking in beneficial stuff, Sahiba and ashpine then why would the nearby land be doing better than the former cornfield plots to which we added that soil? That would mean that the nearby land is also lacking those good things! This just confuses the issue!

To help explain why the nearby land, which has been out of production for 20 years, did better than the recently farmed land to which we added some good soil, we either need to see some great advantage for the nearby land or else see some disadvantage faced by the former cornfield plots.

The passage told us that the difference was that the farmed land (that's the plots where we added the good stuff) were overrun with diseases! Ashpine got the line reference right for that support - that's where the passage gave us an explanation for that difference, and that's where we should have gone to create our prephrase. Why did the native land do better? "Researchers have concluded that this is because fields farmed for many years are overrun with aggressive disease organisms." Boom!