Q14

[jgmartin82]

14. (D)

Question Type: Synthesis (19-39)

We’ve got another open-ended question. The author never really expressed an opinion, so we can expect the author to agree with anything that coincides with the information presented. In we go.

(A) is unsupported. It’s proportional to the number of insects? Maybe, but we get no indication of this, only that there is a relationship. Eliminate.

(B) is out of scope and contradicted. The passage never discusses insects that use plants without giving them an advantage nor harming them. We also see in lines 18-20 that insects played a role in many plants having secondary substances, not few as the answer choice suggests. Eliminate.

(C) is out of scope. We never get information about neither the number of families nor the number of species of plants within each family. Eliminate.

(D) is correct. We are told that mutation is responsible for the appearance of secondary substance, but insects have influenced which secondary substances survive.

(E) is unsupported. The first part looks good; we saw that insects can circumvent chemical defenses in the third paragraph. Also in paragraph 3 we learn that some insects avoid the defenses in some other manner. That leaves the door open for all sorts of stuff. Eliminate.

[erwin.kristen]

Hi - Your explanation for answer D still does not make a lot of sense. It's saying that no substances in plants have appeared as a direct result of insects, however insects have influenced substances that appear in plants. ????

[jan]

I am not perfectly sure about how we can infer D, but I'm guessing in line 19-21, especially the part that says "such substances undoubtedly first appeared".
So although the future mutations were the result of whether they provide a better chance of survival which was "influenced" by the insects that fed on them, the first ones were not in "direct" response to the insects.

Am I on the right track?

[christine.defenbaugh]

I am not perfectly sure about how we can infer D, but I'm guessing in line 19-21, especially the part that says "such substances undoubtedly first appeared".
So although the future mutations were the result of whether they provide a better chance of survival which was "influenced" by the insects that fed on them, the first ones were not in "direct" response to the insects.

Am I on the right track?

Getting close, withjc_4ev!

Lines 17-21 are going to be helpful here. Let's parse out exactly what they say:

1) insects played a major role in plants having these secondary substances today
BUT!
2) those substances first appeared as a result of genetic mutations.

Hm. So, the substances first showed up randomly. It's important to realize that genetic mutations are by their nature random and unplanned. So, the plants didn't think to themselves, hmmmm....you know what would really make this destructive beetle leave me alone? This cool chemical substance!! That's what I've got to start producing!

So, the one major tweak I would make to what you are saying is that ALL genetic mutations were random/not in *direct* response to insects. Plants don't have a brain where they can make decisions about what's in their best interest. They randomly mutated, some producing new chemicals, and the ones that were lucky enough to randomly mutate to produce chemicals that aided their survival were the ones that survived, while the others would have died off.

So, the insects "played a major role" in the way that they reacted to those substances, and the fact that they would sometimes determine which mutations/substances would survive or and which mutations/substances would die out.

And this is exactly what (D) gives us! If every secondary substance has appeared through (random) genetic mutation, that means it did not appear directly in response to insects. But the insects "influenced" which are currently present in today's plants by killing off certain plants and allowing or helping others to survive and reproduce.

I hope that helps clear things up a bit!

[julianalsarhn]

christine.defenbaugh , I totally get your explanation describing why plants' sometimes favorable mutation is not because of direct contact with the insect, but because of random mutation.
But what I don't understand is how we can infer from the passage that absolutely no plant has ever developed a secondary substance in response to an insect. It certainly wouldn't be by mutation (because of your thorough explanation) but just because mutation doesn't involve direct insect contactdoesn't mean that a plant could never produce a secondary substance by direct contact.
It never mentions in the passage that secondary substances can ONLY be produced via mutation, it only states that they started that way. Who's to say that plant A's chemical B reacts with insect Z's chemical Y and creates chemical C? I don't see how the fact that mutation doesn't use direct contact rules out that possibility

"No secondary substance has appeared" just seemed way too strong to me

[andrewgong01]

I understand "D" now but I am unclear about "B" and perhaps it it revolves around what does "few species of plant" constitute quantitatively? I thought it would mean "Some" and was some LSAT trick to make it sound like "few" means really little (like 3 in everyday parlance) while the passage used words like "many" (which in everyday parlance suggests a lot like a majority when it logically only means some) .

I thought "B" was supported on Line 25 when it talks about pollinating because it says it benefited insects without damaging the plants. The impact on plant was that it caused blossoms, which was not stated to have aided or not aided the survival of plant.

Between "D" and "B" when I first took the test, I ruled out "D" because it was extreme in language but line 19 was equally extreme "undoubtedly first appeared... from genetic mutation" upon review. Was there anything about this sentence, line 19, aside from its extreme language, that we should pay attention to in remembering for questions becuase I seem to often miss questions where the answer is supported from a single line, especially when the line is not prominently displayed as like the first/last sentence, and where if we don't recall the line it is hard to answer correctly

[ohthatpatrick]

"few" is the opposite of "most"

Few A's are B = Most A's are ~B

It means "less than 50%". "A few" means 3, but LSAT doesn't try test that difference.

For (B), I would be worried whether I could justify "less than 50% of plant species have benefited from insects".

For (D), I would be worried whether I could justify "0% of secondary substances have been a direct response to insects".

In both cases, I would have to look it up. We're not expected to remember precise quantifiers like this.

In this case, I did happen to remember the passage had said that secondary substances appear as the result of mutations and can get conserved if they pass the muster of natural selection (it also helps if we just have a working understanding of natural selection).

You shouldn't be worrying about how to remember a nitty-gritty proof sentence on the first read (other than trying to make sure that when you read, you try to fully comprehend/process/rephrase sentences as you read them, re-reading them when necessary)

A lot of "inferred/implies/suggests/most likely agree" correct answers are just testing a 'needle in the haystack' ... you have to do a lot of hunting to find your Proof Sentence.

This is where a good Passage Map comes into play. If we knew that P2 was the paragraph that most discussed the interplay between insects/plants in terms of benefit/harm, then we would revisit the specific wording and see that we can't justify "less than 50% of plants benefit" but that we CAN justify "0% of secondary substances appeared in direct response to insects".

Reading Comp is scary-dense. We have read the passages well enough to make quick decisions on some garbage answers so that we have the time for the fact-finding hunts that are required to support some of the correct answers.

[alexia.jablonski]

Could someone please clarify why (E) is incorrect?

According to lines 42-48, insects must either circumvent plants' defenses or eat different plants in order to survive. I interpreted this as meaning that these are the ONLY two options for surviving against toxic plants. I chose (E) because if the only two options are circumventing the plants' defenses (i.e. finding a workaround) or not eating those plants, then developing immunity is not one of those two possible options. Therefore, no insects have evolved "through outright immunity".

Grateful for your insights!

[ohthatpatrick]

They're thinking that "outright immunity" is a form of "circumventing plants' chemical defenses".

You're thinking that they are two separate things, that "outright immunity" doesn't count as a way of "circumventing" defenses.

I think you could make a decent case either way ---
if I have an immunity to your poison, then I have circumvented your chemical defense

But it doesn't sound like a "workaround" so much as a, "I am able to charge straight through this brick wall with no ill effect".

ULTIMATELY, the good news is we don't have to wage this linguistic debate. The answer choice itself specifies that we are intended to think of "outright immunity" as a possible way of "circumventing".

The syntax/logic of that sentence is saying "While many insects have done X, none of them accomplished X using Method A."

Therefore, "outright immunity", according to this answer choice, is not a different tactic from "circumventing", it's a specific form of "circumventing".

Hope that makes sense.

[hayleychen12]

I'm still confused about the "no particular" part of D.

For me, Line 17-20 is just talking about "many plants" and their secondary substances. That does not excludes the possibility of other plants having secondary substances as a direct response to insects.

Any help!

[DPCTE4325]

Hi Patrick!

I’m still so confused as to what you mean by “they’re thinking that outright immunity is a form of circumventing” and how this allows us to rule out E as unsupported?

They're thinking that "outright immunity" is a form of "circumventing plants' chemical defenses".

You're thinking that they are two separate things, that "outright immunity" doesn't count as a way of "circumventing" defenses.

I think you could make a decent case either way ---
if I have an immunity to your poison, then I have circumvented your chemical defense

But it doesn't sound like a "workaround" so much as a, "I am able to charge straight through this brick wall with no ill effect".

ULTIMATELY, the good news is we don't have to wage this linguistic debate. The answer choice itself specifies that we are intended to think of "outright immunity" as a possible way of "circumventing".

The syntax/logic of that sentence is saying "While many insects have done X, none of them accomplished X using Method A."

Therefore, "outright immunity", according to this answer choice, is not a different tactic from "circumventing", it's a specific form of "circumventing".

Hope that makes sense.

[DPCTE4325]

Doesn’t the passage list the various ways in which the insects do circumvent? And outright immunity is never mentioned nor implied.

If anything I thought immunity was ruled out because if insects find a way to circumvent, that seems to imply that insects do NOT have outright immunity to just be able to bulldoze through?

That discussion you're quoting has nothing to do with why we're getting rid of (E).

I was just responding to a poster's confusion about why his interpretation of (E) was incorrect and therefore was not support for (E).

"they" = the passage / LSAT

The reason we're getting rid of (E) is because where can anyone find support for the extreme notion that "No species of insect has ever evolved an outright immunity to a plant's secondary substance"?

[ohthatpatrick]

That discussion you're quoting has nothing to do with why we're getting rid of (E).

I was just responding to a poster's confusion about why his interpretation of (E) was incorrect and therefore was not support for (E).

"they" = the passage / LSAT

The reason we're getting rid of (E) is because where can anyone find support for the extreme notion that "No species of insect has ever evolved an outright immunity to a plant's secondary substance"?