Before scientists learned how to make a synthetic growth hormone, remo

A) scientists learned how to make a synthetic growth hormone, removing it painstakingly - Wrong way to phrase the sentence.
B) scientists had learned about making a synthetic growth hormone, they had to remove it painstakingly - Use of "had" 2 times is wrong.
C) scientists learned how to synthesize the growth hormone, it had to be painstakingly removed - part marked in RED changes the meaning of the sentence. Scientists did not learn to synthesize the hramone itself, they just learned how to make the synthetic harmone.
D) learning how to make a synthetic growth hormone, scientists had to remove it painstakingly - correct and only remaining answer.
E) learning how to synthesize the growth hormone, it had to be painstakingly removed by scientists - Same as C.

Right catch

C and D gramatically both correct, but C changes the intent.

'to make synthetic X' and 'to synthesize X' are different.

OA is C

as everybody has said, C and D are really close. That's why the question,IMO, is hard.

D) Before learning how to make a synthetic growth hormone, scientists had to remove it painstakingly in small amounts from the pituitary glands of human cadavers.

The main problem with D is that "it" refers to "synthetic growth hormone" and not only to synthetic growth hormone. Pronouns refer to the adjectives-noun. In addition, the scientist did not remove the growth hormone, so option C correctly uses the passive voice.

I pick C. For D, the sentence implies that scientists extracted synthetic growth hormone, not naturally occurring growth hormone, from human bodies. This, I think, changes the meaning.

The only thing strange about C is the word "the" preceding "growth hormone." I suppose that if the sentence is referring to a specific growth hormone, then it's okay.

But isn't "scientists" plural in C? Maybe it was edited later.

This is really a typical sc which test profound meaning. C and D are both correct in grammar but have different meanings.
D is illogical jerk because it means that: before scientists learn how to synthesize a hormone, they had to remove it (hormone) from nature (which is one of a step in the hormone synthetic process) --> so if hormone is already there, scientists dont have to synthesize it.
C is rational because it means: before scientists learn to synthesize a hormone, hormone had to be removed from nature (because people have not synthesise it yet so they have to use hormone from nature resource). --> that's the meaning of C.
this idea has come up with me when i've browsed this link, found it is very useful to read Ron's explanation.
https://www.manhattangmat.com/forums/bef ... -t637.html

IMO C, Please see POE, please feel free to pass comments

A. scientists learned how to make a synthetic growth hormone, removing it painstakingly
B. scientists had learned about making a synthetic growth hormone, they had to remove it painstakingly
C. scientists learned how to synthesize the growth hormone, it had to be painstakingly removed
D. learning how to make a synthetic growth hormone, scientists had to remove it painstakingly
E. learning how to synthesize the growth hormone, it have to be painstakingly removed by scientists

A B D -- out - Redundancy , 'make' and 'synthetic' - conveys same meaning.
Between C and E : E --out Modifier error. hence C

Before scientists learned how to make a synthetic growth hormone, removing it painstakingly in small amounts from the pituitary glands of human cadavers.

A) scientists learned how to make a synthetic growth hormone, removing it painstakingly
B) scientists had learned about making a synthetic growth hormone, they had to remove it painstakingly.
C) scientists learned how to synthesize the growth hormone, it had to be painstakingly removed
D) learning how to make a synthetic growth hormone, scientists had to remove it painstakingly
E) learning how to synthesize the growth hormone, it had to be painstakingly removed by scientists Before X, Y happened. X & Y both should be clause. but , here highlighted portion is a afragment, which is not making any sense

1. Verb Seq: Before X, Y happened. Thus , we need past perfect in Y to maintain this seq. Thus, A, B are out.
2. "painstakingly" is adverb. It should modify Verb "removed". Thus , A, D are out.

Before scientists learned how to make a synthetic growth hormone, removing it painstakingly in small amounts from the pituitary glands of human cadavers.
The sentence is meant to say - before scientists learnt how to make synthetic growth hormones , they used to go through the painful way to extract the hormones ( growth hormones) i.e the growth hormones were removed from human cadavers

A. scientists learned how to make a synthetic growth hormone, removing it painstakingly
Sentence fragment . There is no working verb in the sentence - "before scientists learned <> , removing it <>"
the "IT" here refers to "synthetic growth hormone" , rather than "growth hormones" ( it was not the "synthetic growth hormones" that they removed from human cadavers , but was the growth hormones .

B. scientists had learned about making a synthetic growth hormone, they had to remove it painstakingly

*error in tense. The learning of making synthetic hormone , happened after they used to remove growth hormone in a painstaking way . Hence "had" in first part of sentence is incorrect.
* the "IT" in second part of the sentence refers to "synthetic growth hormone " rather than just "growth hormone" , conveying an absurd meaning that "before scientists learned to make synthetic growth hormone , they used to remove synthetic growth hormone from pituitary glands".

C. scientists learned how to synthesize the growth hormone, it had to be painstakingly removed
CORRECT : the "IT" here refers to "growth hormone" , hence conveying a correct meaning.Sentence is framed in a proper Tense.

D. learning how to make a synthetic growth hormone, scientists had to remove it painstakingly
Same issue with "IT" as in A and B.

E. learning how to synthesize the growth hormone, it have to be painstakingly removed by scientists

*Modifier error- doesn't convey who is synthesizing the growth hormone ( comma should immediately follow with the noun scientist . Which is not the case here).
Tense error - messes up the tense issue ( should be "had" instead of "have" , since this action is not happening anymore now and this happened before the scientists learned to synthesize).

-Jyothi

Before scientists learned how to make a synthetic growth hormone, removing it painstakingly in small amounts
from the pituitary glands of human cadavers.

1:meaning analysis
before scientists learned how to make a synthetic growth hormone, they had to remove the growth hormone painstakingly in small amounts from its place.

2:error analysis
sentence fragment. dependent clause+,+ phrase

3:POE
A.
B. scientists had learned about making a synthetic growth hormone, they had to remove it painstakingly
in fact the second sentence's verb must be stated in past participle from + it in the second part refers to a synthetic growth hormone while it should refer to growth hormone

C. scientists learned how to synthesize the growth hormone, it had to be painstakingly removed

D. learning how to make a synthetic growth hormone, scientists had to remove it painstakingly
changes meaning. it implies that before learning how to do x they had to do y+ pronoun reference error "it" refers to a synthetic growth hormone while it should refer to growth hormone

E. learning how to synthesize the growth hormone, it had to be painstakingly removed by scientists
modifier error+ no need for the passive form

A. scientists learned how to make a synthetic growth hormone, removing it painstakingly – a fragment
B. scientists had learned about making a synthetic growth hormone, they had to remove it painstakingly – 1. had learned was a later phenomenon, had to remove was the earlier phenomenon. Use of past perfect for the earlier is wrong. 2. ‘It’ refers to the synthetic hormone. One can’t remove a synthetic hormone from a body; it is only synthesized in a lab.

C. scientist learned how to synthesize the growth hormone, it had to be painstakingly removed – it promptly refers to the growth hormone (natural hormone and not synthetic.)
D. learning how to make a synthetic growth hormone, scientists had to remove it painstakingly – it refers to synthetic growth hormone—wrong
E. Learning how to synthesize the growth hormone, it have to be painstakingly removed by scientists— it have to be – is a typo? In any case, the modification is also wrong. Scientists should appear after the comma.

Before scientists learned how to make a synthetic growth hormone, removing it painstakingly in small amounts from the pituitary glands of human cadavers.

A deep meaning based question

A) scientists learned how to make a synthetic growth hormone, removing it painstakingly-- a fragment -- Any subordinate clause has to be backed by IC and not a modifier.

B) scientists had learned about making a synthetic growth hormone, they had to remove it painstakingly.-- Look at the absurdity of this proposition. -They had to remove it- Not withstanding that the pronoun 'they' tentatively refers to the scientists, we still have the deeper problem of removing a synthetic hormone from the organic glands. A synthetic hormone can be made only outside the body and not within. If done, it will be a natural hormone but not synthetic

C) scientists learned how to synthesize the growth hormone, it had to be painstakingly removed --- Now the pronoun 'it' rightfully' refers to the growth hormone. It is also correct to use the passive voice since there is no indication in the original that scientists did the removing. It could be by anybody.

D) learning how to make a synthetic growth hormone, scientists had to remove it painstaking--- That the scientists had to remove it is not intended in the original.

E) learning how to synthesize the growth hormone, it had to be painstakingly removed by scientists --the same mistake as in B, D, and E.

Before scientists learned how to make a synthetic growth hormone, removing it painstakingly in small amounts from the pituitary glands of human cadavers.

(A) scientists learned how to make a synthetic growth hormone, removing it painstakingly Sentence fragment. Also, "it" refers to synthetic growth hormone, which cannot be in human glands. Eliminate.

(B) scientists had learned about making a synthetic growth hormone, they had to remove it painstakingly "it" refers to synthetic growth hormone, which cannot be in human glands. Eliminate.

(C) scientists learned how to synthesize the growth hormone, it had to be painstakingly removed Correct answer.

(D) learning how to make a synthetic growth hormone, scientists had to remove it painstakingly "it" refers to synthetic growth hormone, which cannot be in human glands. Eliminate.

(E) learning how to synthesize the growth hormone, it had to be painstakingly removed by scientists Meaning change - we do not know that it was the scientists who removed the hormone from pituitary glands. Eliminate.

Hope this helps.

Dear Friends,

Here is a detailed explanation to this question-
Meaning is crucial to solving this problem:
Understanding the intended meaning is key to solving this question; the intended meaning of this sentence is that before scientists learned how to synthesize the growth hormone, the only way to procure the hormone was to painstakingly remove it in small amounts from the pituitary glands of human cadavers.

Concepts tested here: Meaning + Modifiers + Tenses + Verb Forms

• In a “phrase + comma + noun” construction, the phrase must correctly modify the noun; this is one of the most frequently tested concepts on GMAT sentence correction.
• If a sentence contains multiple past actions, the past perfect tense (marked by the use of the helping verb “had”) is used to refer to all but the most recent action; the simple past tense is used to refer to the most recent action.

A:
1/ This answer choice fails to form a complete sentence; as "learned" is part of a modifying phrase, and "removing" is a present participle ("verb+ing"), there is no active verb to act upon the subject pronoun "it".

B:
1/ This answer choice alters the meaning of the sentence through the phrases "learned about making a synthetic growth hormone" and the clause "they had to remove"; the construction of these phrases incorrectly implies that before scientists learned that it is possible to synthesize the growth hormone, the scientists themselves had to extract the hormone in small amounts from cadavers; the intended meaning is that before scientists learned how to synthesize the growth hormone, the only way to procure the hormone was to painstakingly remove it in small amounts from the pituitary glands of human cadavers.
2/ Option B incorrectly uses the past perfect tense verb "had learned" to refer to the later of two actions that concluded in the past - scientists learning how to synthesize the growth hormone and the growth hormone having to be painstakingly removed in small amounts from the pituitary glands of human cadavers; remember, if a sentence contains multiple past actions, the past perfect tense (marked by the use of the helping verb “had”) is used to refer to all but the most recent action; the simple past tense is used to refer to the most recent action.

C: Correct.
1/ This answer choice acts upon the subject pronoun "it" with the active verb "had to be...removed" to form a complete thought, producing a complete sentence.
2/ Option C uses the phrase "scientists learned how to synthesize" and the clause "it had to be painstakingly removed", conveying the intended meaning - that before scientists learned how to synthesize the growth hormone, the only way to procure the hormone was to painstakingly remove it in small amounts from the pituitary glands of human cadavers.
3/ Option C correctly uses the simple past tense verb "learned" to refer to the later of two actions that concluded in the past - scientists learning how to synthesize the growth hormone and the growth hormone having to be painstakingly removed in small amounts from the pituitary glands of human cadavers.

D: Trap.
1/ This answer choice alters the meaning of the sentence through the clause "scientists had to remove it"; the construction of this clause incorrectly implies that the scientists themselves had to extract the hormone in small amounts from cadavers; the intended meaning is that the only way to procure the hormone was to painstakingly remove it in small amounts from the pituitary glands of human cadavers.

E:
1/ This answer choice incorrectly uses "Before learning how to synthesize the growth hormone" to modify the pronoun "it", which refers to "the growth hormone", illogically implying that the growth hormone learned how to synthesize itself; the intended meaning is that scientists learned how to synthesize the growth hormone; remember, in a “phrase + comma + noun” construction, the phrase must correctly modify the noun.
2/ Option E alters the meaning of the sentence through the phrase "removed by scientists", incorrectly implying that the scientists themselves had to extract the hormone in small amounts from cadavers; the intended meaning is that the only way to procure the hormone was to painstakingly remove it in small amounts from the pituitary glands of human cadavers.

Hence, C is the best answer choice.

To understand the concept of "Phrase Comma Subject" and "Subject Comma Phrase" on GMAT, you may want to watch the following video (~1 minute):



To understand the concept of "Past Perfect Tense" on GMAT, you may want to watch the following video (~2 minutes):



All the best!
Experts' Global Team

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