Scientists have recently discovered that the ultra thin, layered const

Question

Scientists have recently discovered that the ultra-thin, layered construction of a butterfly’s wings—the same construction that makes some butterflies shimmer via the phenomenon of iridescence—also enables the insect to control how much heat energy is absorbed by its wings and how much is reflected away.

(A) wings, the same as the one making some butterflies shimmer via the phenomenon of iridescence, are enabling

(B) wings, which is the same one that makes some butterflies shimmer via the phenomenon of iridescence, that also enables

(C) wings is the same as the one that makes some butterflies shimmer via the phenomenon of iridescence, enabling

(D) wings—the same construction that makes some butterflies shimmer via the phenomenon of iridescence—also enables

(E) wings—of the same construction that makes some butterflies shimmer via the phenomenon of iridescence—also enable

SaraiYaseenGMAT · Accepted Answer

A.wings, the same as the one making some butterflies shimmer via the phenomenon of iridescence, are enabling
   Take it one clause (subject+verb) at a time: scientists (subject) have discovered (verb) that the construction (subject) are enabling (verb). "Construction" is singular, and "are enabling" is plural.

B: wings, which is the same one that makes some butterflies shimmer via the phenomenon of iridescence, that also enables
   scientists (subject) have discovered (verb) that the construction (subject), but now where is the verb for 'construction'? You cannot complete the clause 'that construction..." with "that enables".

C: wings is the same as the one that makes some butterflies shimmer via the phenomenon of iridescence, enabling
   scientists (subject) have discovered (verb) that the construction (subject) is (verb) the same as the one (meaning 'construction') that makes butterflies shimmer. Your clauses have now ended! The 'enabling...' after the comma modifies (adds descriptive information to) the sentence and is not part of the clauses.
 There is no grammatical error here; however, you must ask yourself whether this the intended meaning ! Does the sentence mean to say that scientists have discovered that the the construction of the wings is the same as the one that makes butterflies shimmer? Let's look at D....

D: wings the same construction that makes some butterflies shimmer via the phenomenon of iridescence also enables
   First of all, there should be a comma after "wings", but let's assume that this is a typo.

scientists (subject) have discovered (verb) that the construction (subject)  also enables(verb) the insect to control the absorption of heat.  This is more likely the intended meaning, namely, that scientists have found a second purpose for the way butterflies' wings are constructed.

E: wings of the same construction that makes some butterflies shimmer via the phenomenon of iridescence also enable
"the construction"... "enable"-- subject-verb agreement error.

daagh · Answer

Scientists have recently discovered that the ultra-thin, layered construction of a butterfly’s wings—the same construction that makes some butterflies shimmer via the phenomenon of iridescence—also enables the insect to control how much heat energy is absorbed by its wings and how much is reflected away.

I am afraid that the sentence is being parsed wrongly down here. Let's not get into thinking that the ultrathin is any kind of a proper noun or specific name. It is just an adjective meaning extremely thin. The real subject of the sentence is the "construction" that is modified by two back - to - back coordinate adjectives namely ultrathin and layered. In the light of the fact that such a construction is making the butterflys shimmer and is enabling the butterflys to control the heat mechanism, "also enables" is good enough.

Now on to the choices.

A. wings, the same as the one making some butterflies shimmer via the phenomenon of iridescence, are enabling -- -are enabling is SV error. 
 
B. wings, which is the same one that makes some butterflies shimmer via the
phenomenon of iridescence, that also enables --  1. Which is wrongly modifying wings. 2. Wings, which is an awful SV error. 3. This sentence is a fragment.  
C. wings is the same as the one that makes some butterflies shimmer via the
phenomenon of iridescence, enabling ----  a subtle meaning issue here. This choice wrongfully makes the heat-control mechanism as an effect of the shimmering by placing the heat-controlling as a modifier of shimmering.  
D. wings—the same construction that makes some butterflies shimmer via the phenomenon of iridescence—also enables --  Correct choice.  
E. wings—of the same construction that makes some butterflies shimmer via the phenomenon of iridescence—also enable ---  also enable is SV error.

skovinsky · Answer

Hi!

I'm not sure if you have a specific question or are just wondering about the sentence in general, but we'll look at the whole thing.

A commonly tested grammar topic on the GMAT is modification. Here's the general rule:

This particular sentence is all about modification - and we recognize that by the parenthetical comment in the middle:

(I included the commas because those are our signals that we're almost certainly being tested on modification).

So, whatever that phrase is modifying should be directly before or after the phrase.

In the original sentence, the subject of the modifying phrase isn't as clear as the GMAT demands; it could be the wings or the layered construction of the wings. When there's any kind of modification ambiguity, it's extremely unlikely that the choice will be correct.

Looking at the remaining choices:

B) has the same issue as (A) (adding "which is" doesn't make it any clearer) - eliminate.

C) has the same issue as (A) - eliminate.

D) begins with 'the same construction as' - this fixes the ambiguity issue as we now know that we're talking about the layered construction - looks good!

E) "of the same construction" doesn't make sense when read into the sentence - "of" messes up the meaning and flow - eliminate.

Choose (D)!

Nightmare007 · Answer

I don't know why but i think this problem is itself has wrong construction -that the ultrathin, I find this sentence incomplete.

Skywalker18 · Answer

mikemcgarry  , sayantanc2k  ,  RonPurewal  ,  daagh  , GMATNinja  , egmat  , other experts -- please englighten

1. In option A , if we change are enabling to enable , then option A will be correct ?

Scientists have recently discovered that the ultra-thin, layered construction of a butterfly’s wings—the same construction that makes some butterflies shimmer via the phenomenon of iridescence—also enables the insect to control how much heat energy is absorbed by its wings and how much is reflected away.

2. Is the modifier "the same as the one making .. iridescence" an absolute phrase?

3. Though I was able to select the correct answer , i took longer than usual because of the presence of a comma in "ultrathin, layered construction of a butterfly’s wings" since initially, I assumed layered construction to be a modifier .
Is the presence of this comma okay here?

mikemcgarry · Answer

Dear Skywalker18 , I'm happy to respond.

This is a very good SC question, and very challenging, as MGMAT material often is. The adjective " ultrathin " is a very sophisticated adjective, not often seen in non-scientific writing. Thus, in the phrase " the ultrathin, layered construction of a butterfly’s wings ," the adjectives " ultrathin " and " layered " are in parallel and, as is often the case in constructions in which a pair of parallel adjectives modifies a noun, the two adjectives are separated by a comma. If you didn't recognize " ultrathin " as a adjective, then I could see that this would make the sentence much more confusing. Any time we don't know the part of speech of a single word, it makes the sentence much harder to interpret. The construction " the same as . . . " is a unmitigated disaster in this sentence. This construction is an appositive phrase and would be correct only if the target is absolutely unambiguous. Humphrey Bogart achieve peak star status in the movie Casablanca , the same that earned him his first Oscar nomination . There, the construction is 100% unambiguous. Even here, the construction is a bit casual, colloquial, journalistic, not typical of academic writing. It is definitely not the way a high-brow sophisticated writer would convey the information. In (A), the phrase is a complete train wreck because we are wondering: the same as the wings? the same as the construction? Choice (D), the OA, cleans up this ambiguity. The verb at the end of (A) is the least of the problems with that choice. Does all this make sense? Mike

BoundMan · Answer

generis

Does the option D need and before "also enables" or "- " does the work?
(D) wings—the same construction that makes some butterflies shimmer via the phenomenon of iridescence—also enables

generis · Answer

akash7gupta11  , this basis of this question is good. Answering it is not so easy without a boatload of jargon that you do not need.

The em dashes do not function as an AND.
We do not need AND because we have a  that-clause  and the word ALSO.

• ALSO  
 Also  is an  adverb  that means  in the same way, similarly, likewise,  or  in addition

Correct  : X that does Thing1 ALSO does Thing2.
  Nonsensical  : X that does Thing1  and  also does Thing2.

The structure about which you ask could be written this way: 
→  X blah blah—X that does P—also does Q. 
→  X that makes P   also enables Q  . 
→  The . . . construction of a butterfly's wings—the same construction that makes P happen—also enables Q to happen.

• ALSO already implies two results

The em dashes do not do the work of AND. 
The modifier and the word  also  convey the AND (iridescent appearance + regulation of heat)

-- One result of the subject, construction, is already mentioned in the modifier set off by em dashes. 
(That modifier is called a "resumptive" modifier. It repeats the subject and gives additional information.)

-- That modifier gives us  one  result produced by the  construction  of a butterfly's wings: some butterflies shimmer (iridescently, like an oyster shell).

-- That construction produces a second result: a butterfly can control the amount of heat absorbed or reflected by its wings.

• no AND  
We cannot insert AND. 
One result of the subject has already been presented by the that-clause. The second result is signaled by the word ALSO.

If we insert  and  before  also , the  and  
ruins the parallelism of   X that does P also does Q . 
When we add  and,  we get   X that does P and also does Q  
"And also" is nonsensical. 
 
 Wrong: X of a butterfly's wings —X that does P—AND also does Q. 
 Correct: X of a butterfly's wings—X that does P—ALSO does Q.

Stripped, wrong:   X that does P and also does Q 
 Stripped, correct:   X that does P also does Q

The word ALSO tells us that we are reading a second result.

• similar sentences

Try inserting the word AND before also in each sentence below.
The AND should not sound correct. 
The that-clause already defines one result. The word "also" means "in a similar way  ,"

A butterfly's wing, constructed in a way that makes the insect appear iridescent, also allows the insect to regulate its heat absorption.

The construction of a butterfly's wing that makes the insect appear iridescent also allows the insect to regulate its heat absorption.

Hope that helps.

mykrasovski · Answer

Lots of good analysis by experts such as  generis .

An alternative solution is to simplify the sentence.

Scientists have recently discovered that      construction  of a butterfly's wings,  ,  are enabling  the insect    .

Clearly, there is a Subject-Verb problem because  construction  is singular, and the phrase  are enabling  needs a plural subject. Quick scan of the answer choices shows that only options B and D have a verb that will "match" with a singular  construction .

Option B does not work because of several reasons. One reason is the modifier "which" that is ambiguous (does it refer to construction or wings?), and another reason is a word  that  that attempts to introduce a parallel structure, i.e.  scientists discovered that construction       that enables     should have a verb.

(A) wings, the same as the one making some butterflies shimmer via the phenomenon of iridescence, are enabling

(B) wings, which is the same one that makes some butterflies shimmer via the phenomenon of iridescence,  that  also enables

(C) wings is the same as the one that makes some butterflies shimmer via the phenomenon of iridescence, enabling

(D) wings—the same construction that makes some butterflies shimmer via the phenomenon of iridescence—also enables

(E) wings—of the same construction that makes some butterflies shimmer via the phenomenon of iridescence—also enable

generis · Answer

mykrasovski - good analysis. I was answering a specific question, though, about whether the word AND was needed in the context of a sentence that used an em dash and a resumptive modifier.

In my original post, I will highlight the question that I answered. (It's hard to see.) This is the question I answered: I think that is the question that I was answering. It's true that there are easier ways to choose (D). (Figure out what is wrong with B, just as you did.) I think the question was about the structure of (D) in general (and in particular, why no "and" is needed).

Palladin · Answer

generis , isn't the sentence " the same construction that makes ... " an appositive?
So, the original sentence should make sense if the appositive is removed.
However, the sentence " Scientists have recently discovered that the ultra thin, layered construction of a butterfly's wings  also  enables the insect to control ... " seems like it doesn't need  also .
Could you explain?

generis · Answer

Palladin , we are in a bind. Also is not underlined. The sentence is good. The guideline, yes, says that the core meaning of the original sentence should make sense if the appositive is removed (a resumptive modifier is a type of appositive). I so regret using ANY jargon. *facepalm* After I discuss resumptive modifiers and apposition quickly, let's call that thing between the em dashes a modifier and check its meaning. A resumptive modifer is a special kind of appositive according to the grammar and language source that I use often use.** Makes sense. A resumptive modifier simply repeats the noun and gives additional information. The “special” quality to the resumptive modifier is simply that it literally renames the noun. (“the same construction ”) Resumptive and summative modifiers are sophisticated ways to vary prose, as is all apposition. Resumptive modifiers are rhetorically effective if used sparingly. Now we come to the part in which I say that the modifier between the em dashes cannot be removed in the way we normally think about non-restrictive modifiers. The second mention of "construction" is essential to the meaning of the non-underlined portion of the sentence. The first mention of "construction" is not accompanied by a that-clause. The second mention is accompanied by a that-clause. ALSO is in the non-underlined portion of the sentence and cannot be removed. This is (D) Scientists have recently discovered that the ultra-thin, layered construction of a butterfly’s wings—the same construction that makes some butterflies shimmer via the phenomenon of iridescence—also enables the insect to control how much heat energy is absorbed by its wings and how much is reflected away. Sometimes commas and em dashes are unavoidable. This sentence is good prose. Technically, em dashes signal nonessential material that can be removed without changing the core meaning of the sentence. Parentheticals typically are just that: asides. Those characterizations are not true in this case. We cannot remove the bracketed material. The core meaning of the sentence changes. The sentence intends to tell us that scientists have discovered a second property of the construction of a butterfly’s wings. Pretend that we can remove “also.” (We cannot actually do so because also is in the non-underlined portion.) This is (D) with the modifier and also removed: Scientists have recently discovered that the ultra-thin, layered construction of a butterfly’s wings enables the insect to control how much heat and energy is absorbed by its wings and how much is reflected away. The core meaning is lost. The construction does TWO things. (And both of those things are cool.) Where is the other thing that the construction of a butterfly’s wings does? I can understand wanting the rules to work all of the time. Only a very few rules do so, such as subject/verb agreement, pronoun/noun agreement, subject/object pronoun use, comma splices, and fragments. In this case, I would argue that rhetorical effectiveness requires this kind of punctuation. I rewrote the sentence three different ways. None was as effective as this construction. Alternatively, call option D the “best of the five.” Finally, if you think that a better option exists, argue your case and tag me.

This sentence is well-written. It is more than comprehensible. I know that SC can often seem like an inexact science. It is. I would not toss the best answer because it did not adhere to rules about essential and non-essential information. And if you do think that a better option exists, that's okay. You have to argue your case to convince me, but that's okay. Good instincts. +1

Palladin · Answer

generis , thank you for the insight and the acknowledgment.

As long as jargon simplifies things, you don't have to regret using it. It's a short way to portray the point. Also, people can read more about the keywords later.
One wouldn't say "The word people use to particularly refer to me is Bruce Wayne" instead of "My  name  is Bruce Wayne", would they?

Since  also  is part of the correct option, one would explain it away with suitable theories.
Paraphrasing Sherlock, "One must twist theories to suit facts, instead of the other way around".

One comes to option D not because it is right but because other options are wrong.
I only wanted to know how  right  it is.

Will the following sentence be valid?
 Scientists have recently discovered that the ultra-thin, layered construction of a butterfly’s wings, which makes some butterflies shimmer via the phenomenon of iridescence, enables the insect to control how much heat energy is absorbed by its wings and how much is reflected away. 
 'Which'  refers to the  construction  and not the  wings . (A valid case when it comes to prepositional phrases.)
Doesn't it depict that the construction of a butterfly's wings has two functionalities?

generis · Answer

Palladin ,

I would make a terrible Watson. I had better amend my statement. I could not write a sentence that I liked as much as this one from the perspective of a writer, an editor, and a lover of prose. I know how to write a sentence that expresses the intended meaning of the sentence. What I could not do without using apposition of some sort was to construct a sentence as elegant as this one is. Your sentence is grammatical. But if we follow the "excise nonessential material" approach, then your sentence does not mean what this sentence intends to say. In your sentence, the which -clause is nonessential. Turnabout is fair play. I can remove the which-clause. Scientists have recently discovered that the ultra-thin, layered construction of a butterfly’s wings enables the insect to control how much heat energy is absorbed by its wings and how much is reflected away. That sentence does not mean that the construction of a butterfly's wings has two functionalities. The fact of iridescence is interesting. Unfortunately, even when the sentence is written with the restrictive that , it loses all of its depth and cadence. Scientists have recently discovered that the ultra-thin, layered construction of a butterfly’s wings makes some butterflies shimmer via the phenomenon of iridescence and enables the insect to control how much heat energy is absorbed by its wings and how much is reflected away. YAWN. Grammatical. Meaning: the construction of a butterfly's wings has two functionalities. The sentence is flat. A little better, but not by much: Scientists have recently discovered that the ultra-thin, layered construction of a butterfly’s wings that makes some butterflies shimmer via the phenomenon of iridescence also enables the insect to control how much heat energy is absorbed by its wings and how much is reflected away. Bottom line? Grammatically, option D is the best. You wrote: The strategy in SC is indeed to eliminate four wrong options, not to look for the one good or correct option. I am not prepared to say that option D is not "right." Something about this whole exercise is wearisome, perhaps inapposite. Does D serve? Is it better than the others? We mark the answer and move on. I really cannot tell what you are trying to say or ask. Perhaps it is this question: should I eliminate a question in which I can remove non-essential information and thereby make the option ungrammatical? Answer: probably not. It depends on the question, and such questions are very rare.

CrackverbalGMAT · Answer

This question is based on Subject-Verb agreement, Modifiers, and Construction.

Option A contains a subject-verb disagreement - layered  construction  of a butterfly's wings, the same as the one making some butterflies shimmer via the phenomenon of iridescence,  are enabling .  The subject is “construction”, so the verb must be ‘is enabling’.  The phrase “the same as the one making some butterflies shimmer” is awkwardly phrased. So, Option A can be eliminated.

Option B is a sentence fragment. The last part of the sentence is made up of two dependent clauses –  “which is…..iridescence”  and  “that also enables….away” . There is no verb to complete the idea. So, Option B can be eliminated.

Option C is grammatically correct. However, there is a subtle change in the meaning. This option gives more emphasis to the construction being the same as the one that makes some butterflies shimmer via iridescence. This option puts the information that the construction enables the insect to control how much heat energy is absorbed by its wings and how much is reflected away in the form of a modifier.  Because of this change in meaning, Option C can be eliminated.

Option D is clear because of the modifier placed in between dashes. This option also maintains subject-verb agreement.  The verb ’enables’ agrees with the subject.  So, Option D is the best of all the options .

Option E has a subject-verb disagreement - layered  construction  of a butterfly's wings—of the same construction that makes some butterflies shimmer via the phenomenon of iridescence—also  enable . The verb ‘enable’ does not agree with the subject ‘construction’. The preposition ‘of’ is redundant. So, Option E can be eliminated.

Therefore, D is the most appropriate option.

Jayanthi Kumar.

VerbalBot · Answer

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