V08-12

Question

In a recent  study, Harvard Scientists have linked a molecule to PGC-1 alpha FNDC5, a protein that enhances brain health, not only as promoting the development of new nerves and synapses in the hippocampus of the adult brain, but also as preserving  existing brain cells.

A. study, Harvard Scientists have linked a molecule to PGC-1 alpha FNDC5, a protein that enhances brain health, not only as promoting the development of new nerves and synapses in the hippocampus of the adult brain, but also as preserving
B. study by Harvard scientists, a molecule has been linked to PGC-1 alpha FNDC5, a protein enhancing brain-health not only promotes the development of new nerves and synapses in the hippocampus of the adult brain, but also preserves
C. study, Harvard Scientists have linked a molecule to PGC-1 alpha FNDC5, a protein that enhances brain health by not only promoting the development of new nerves and synapses in the hippocampus of the adult brain, but also preserving 
D. study, Harvard Scientists have linked a molecule with PGC-1 alpha FNDC5, which is a protein that enhances brain health, promotes the development of new nerves and synapses in the hippocampus of the adult brain and preserves
E. study, Harvard Scientists have linked a molecule with PGC-1 alpha FNDC5, a brain health enhancing protein, promoting the development of new nerves and synapses in the hippocampus of the adult brain and preserving

Bunuel · Answer

Official Solution:

In a recent  study, Harvard Scientists have linked a molecule to PGC-1 alpha FNDC5, a protein that enhances brain health, not only as promoting the development of new nerves and synapses in the hippocampus of the adult brain, but also as preserving  existing brain cells.

A. study, Harvard Scientists have linked a molecule to PGC-1 alpha FNDC5, a protein that enhances brain health, not only as promoting the development of new nerves and synapses in the hippocampus of the adult brain, but also as preserving
B. study by Harvard scientists, a molecule has been linked to PGC-1 alpha FNDC5, a protein enhancing brain-health not only promotes the development of new nerves and synapses in the hippocampus of the adult brain, but also preserves
C. study, Harvard Scientists have linked a molecule to PGC-1 alpha FNDC5, a protein that enhances brain health by not only promoting the development of new nerves and synapses in the hippocampus of the adult brain, but also preserving 
D. study, Harvard Scientists have linked a molecule with PGC-1 alpha FNDC5, which is a protein that enhances brain health, promotes the development of new nerves and synapses in the hippocampus of the adult brain and preserves
E. study, Harvard Scientists have linked a molecule with PGC-1 alpha FNDC5, a brain health enhancing protein, promoting the development of new nerves and synapses in the hippocampus of the adult brain and preserving

A. The idiom “enhance X AS Y” is wrong. Therefore the structure “a protein enhances brain health AS promoting…” is incorrect. The correct usage would be “a protein enhances brain health BY promoting…”.
 
B. The passive construction “has been linked” does not make it clear who linked the molecule to PGC-1 alpha FNDC5. The part “a protein enhancing brain-health not only promotes the development of new nerves and synapses in the hippocampus of the adult brain, but also preserves…” is an independent clause separated by a comma. The objective is to make the part “a protein..” an appositive phrase modifier for the noun “PGC-1 alpha FNDC5” - the construction on option B makes “protein” an independent noun instead of an appositive.
 
 C. CORRECT.  The appositive “protein that ….” correctly modifies the noun “PGC-1 alpha FNDC5”. The idiom “enhances X by Y'' is correct - “enhances brain health ..by promoting.” In the construction “not only X, but also Y”, parallelism is correctly maintained between “promoting” and “preserving”.
 
D. The verbs “enhances”, “promotes'' and “preserves” are wrongly constructed in parallel, making them three independent actions not bearing on each other. This construction does not make it clear that the enhancement is done by promoting and preserving.
 
E. The present participle phrases “promoting….” and “preserving…” wrongly refer to the subject of the preceding clause “Harvard Scientists”. This construction implies that the Harvard Scientists promotes the development of new nerves and synapses in the hippocampus and preserves the existing brain cells. Moreover it is not clear that the enhancement is done by promoting and preserving.

Answer: C

Will2020 · Answer

sayantanc2k   GMATNinja

In D, the 2 modifiers in a row: " Linking a molecule PGC-1 alpha to FNDC5 ,  a protein that enhances the expression of brain-health ,  Harvard scientists ..." is ok? Because the second modifier is referring to the first modifier, right? Many Tks!

GMATNinja · Answer

The issue with (D) isn't that it's inherently wrong to use two modifiers in a row. Plenty of perfectly acceptable sentences do this. The issue is that the meaning is unclear.

Yes, the  intended  meaning in choice (D) seems to be that "FNDC5" is "a protein that enhances the expression of brain-health." But on first read, it might seem as though the entire phrase "Linking a molecule...." is describing "a protein," when, in fact, it should be describing the scientists. Can you figure that out by reading the sentence multiple times? Maybe. But the potential ambiguity and confusion makes it an inferior option to (C), in which it's crystal clear that the researchers are doing the linking.

The takeaway: don't think about modifier usage in terms of inflexible rules. The real question is whether the modifier is clear and logical, especially relative to other answer choices.

I hope that answers your question!

David nguyen · Answer

— Wait. So a molecule PGC-1 alpha FNDC5 is different to a molecule to PGC-1 alpha FNDC5 right?
 
—Doesn't (C) change the meaning of the original sentence? They were the Scientists who did the job. Now they are the researchers.

"Harvard Scientists have linked a molecule to PGC-1 alpha FNDC5, a protein that enhances the expression of brain-health, not only as promoting the development of new nerves and synapses in the hippocampus...."

I am confused with the sentence. Which one is the subject? Is it the   or   or   or  ?

Abhishekrao12 · Answer

C. In a recently conducted study by Harvard scientists, the researchers have linked a molecule to PGC-1 alpha FNDC5, a protein that enhances the expression of brain-health, saying that it not only promotes the development of new nerves and synapses in the hippocampus of the adult brain, but also preserves existing brain cell

In this option, saying has to modify the action of the previous clause . 
verb-ing modifier can do either of the two things : 1) How the action happened ? or 2 ) what was the result of the previous action. 
I dont think that saying something can help to modify the previous action of linking properly. Just because the scientists say something about the proteins doesnt help in explaining the previous clause. But the OA is option C) Can you please help with this ?

E. In a recently conducted study by Harvard scientists, which linked a molecule PGC-1 alpha to FNDC5, a protein enhancing the expression of brain-health, it not only promotes the development of new nerves and synapses in the hippocampus of the adult brain, but also preserves existing brain cells

This seems to be better answer compared to the rest of the options. which can modify the word 'study' even though its next to scientist. 
The pronoun ambiguity for the word 'it' is similar to the one in option C).

GMATNinja

GMATNinja · Answer

Yes. The first option (as in choice B) suggests that "PGC-1 alpha FNDC5: IS the molecule. The second option (as in choice C) refers to two distinct things that have been linked (the "molecule" and "PGC-1 alpha FNDC5").

Yes, it does! But, as explained in  this post , there is nothing special about the meaning in choice (A), and we certainly do not have to stick with it.

Well, the  subject  is the  scientists . And those scientists have linked two things: (1) a molecule and (2) PGC-1 alpha FNDC5.

The phrase starting with "a protein..." simply modifies (gives us more information about) "PGC-1 alpha FNDC5" - What is "PGC-1 alpha FNDC5"? It's "a protein that enhances...".

Instead of worrying about whether an -ing modifier literally answers the two specific questions you mentioned, just ask yourself, "does it give me more information about the clause or the action?"

But, if you like, you could say that the "saying..." part tells us more about what the researchers did when they linked the molecule and the protein. It gives us more information about the "linking" action, and, in doing so, modifies the clause.

You could also think of the "linking" as the primary action and the "saying" as secondary action that occurs under the umbrella of the "linking". "Have linked" is an ongoing action, and, as part of that process, the researchers said "that it not only promotes the development of new nerves and synapses..." Again, the "saying" modifier tells us more about the "linking" action and, in doing so, tells us more about how the "linking" action happened.

If we remove the "which" clause from (E), we are left with, "In a recently conducted study by Harvard scientists, it not only promotes the development of new nerves and synapses in the hippocampus of the adult brain, but also preserves existing brain cells." The opening modifier seems to describe "it", making it sound as though "it" promotes development IN a recently conducted study. So what happened in the study? "It" promotes development...?? That's not quite right because the "promoting" isn't something that only happens IN the study.

Compare that to choice (C), where the opening modifier clearly describes the "researchers". What happened in the study? The researchers  linked  A to B. So it's the  linking  that happens IN the study, not the  promoting  (as in E), and that makes much more sense.

I hope this helps!

warrior1991 · Answer

GMATNinja   AndrewN 
 VeritasKarishma   AjiteshArun

Option E has a which preceded by comma . Here some people are rejecting on the basis that "which" is incorrectly referring to Harvard Scientists.

I think "which" is referring to the "study" and  NOT TO  "by harvard scientists" because it is a prepositional phrase.

Am I correct ??

AndrewN · Answer

Hello,  warrior1991 . You have it just right. A  which  clause is not used to refer to people anyway; a  who  clause would be needed instead. I was fine with (E) until I reached  it . The shell of the sentence, without the embedded clause and appositive phrase, then states,

In a recently conducted study by Harvard Scientists,  it  not only promotes the development of new nerves and synapses...

What? The study promotes such development? I have to follow more Harvard scholarship if so. This problematic  it  is the nail in the coffin, and we need not consider (E) any further.

Well done on your part. Thank you for bringing the question to my attention.

- Andrew

Veenu21 · Answer

Can someone please help, 
We are saying that "it" in "E" is wrong as it doesn't have any proper antecedent. So in "C" what is the antecedent for same "it"?
Also, is the usage of "which" in "E" is wrong?

GMATNinja · Answer

The "which" clause in (E) isn't terrible. What linked a molecule PGC-1 alpha to FNDC5? The recently conducted study . Is that inherently WRONG? Maybe not. But what linked a molecule to PGC-1 alpha FNDC5 in (C)? The researchers . This makes a bit more sense -- the researchers are the ones who did the linking, not the study itself. So that gives us one vote in favor of (C) over (E). The bigger issue is uncovered when we strip out the "which" clause from (E), as explained at the end of this post and again in this post . As for the antecedent of the "it" in (C), we have two contenders: (1) a molecule or (2) PGC-1 alpha FNDC5 (the protein). So, which one of these makes the most sense? We know that the protein enhances the expression of brain-health And what do we know about the "it"? Well, whatever "it" is, it (1) promotes the development of new nerves and synapses in the hippocampus of the adult brain and (2) preserves existing brain cells. So "it" does two things that presumably are good for the brain. And since the protein enhances the expression of brain-health, it makes sense that the protein is the " it " that (1) promotes {...} in the hippocampus of the adult brain and (2) preserves existing brain cells. That said, you could argue that the "it" refers to "molecule" in (C) and that, as a result, the meaning is a bit ambiguous. But we have bigger problems in the other choices, so, using POE, we are left with (C) as our best choice. Keep in mind that this is NOT an official question, and most unofficial questions are at least a bit flawed in some way

.

Bunuel · Answer

The question or/and solution has been revised and edited. Thank you  sayantanc2k  !!!

AndrewN · Answer

While you are revising/editing, you ought to remove the last few words of answer choice (C), specifically those that appear in the non-underlined portion that follows:  existing brain cells . Technically speaking, these extra words would make (C) inarguably redundant.

- Andrew

Bunuel · Answer

_________________________
Fixed the typo. Thank you!

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