Researchers now regard interferon as not a single

Hi !!

The word "play" is not for the family, it is for "the molecules". ...."the molecules that play....". "That" is essential over here because if you remove it, the essential information defining what roles the complex molecules play will be lost.

Hence, C is the right choice and no error with "play".

Hope it helps

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Isn???t C supposed to be : not as a single substance but as a biological family of complex molecules that plays

I think ???A biological family??? should considered as a singular noun...
Can anyone explain this please?

Thanks!

C. not as a single substance but as a biological family of complex molecules that play

Hello Everyone!

Let's take a look at this question, and figure out how to get to the correct answer quickly! Here is the original question, with any major differences between each answer highlighted in orange:

Researchers now regard interferon as not a single substance, but it is rather a biological family of complex molecules that play an important, though not entirely defined, role in the immune system.

A. as not a single substance, but it is rather a biological family of complex molecules that play
B. as not a single substance but as a biological family of complex molecules playing
C. not as a single substance but as a biological family of complex molecules that play
D. not to be a single substance but rather a biological family of complex molecules playing
E. not as a single substance but instead as being a biological family of complex molecules that play

After glancing over the major differences between each answer, one thing pops out right away: parallelism! We have two items we're dealing with: a single substance & a biological family of complex molecules. To make this sentence sound clear and correct, it's best to use parallel structure to refer to both items. So let's see which answers use parallel structure, and eliminate those that don't.

A. as not a single substance, but it is rather a biological family of complex molecules that play --> WRONG / NOT PARALLEL
(For this to be parallel, it would need to say "as not a single substance, but a biological family."

B. as not a single substance but as a biological family of complex molecules playing --> WRONG / NOT PARALLEL
(Again, for this to be parallel, it would need to say "as not a single substance but a biological family."

C. not as a single substance but as a biological family of complex molecules that play --> CORRECT / PARALLEL
(This uses parallel structure to start both phrases by beginning both with the words "as a...")

D. not to be a single substance but rather a biological family of complex molecules playing --> WRONG / NOT PARALLEL
(For this to be parallel, it would need to say "not to be a single substance, but to be a biological family...")

E. not as a single substance but instead as being a biological family of complex molecules that play --> WRONG / NOT PARALLEL
(For this to be parallel, it would need to say "not as a single substance, but as a biological family...")

Well there you have it! Option C is the correct answer because it is the only answer that uses parallel structure!


Don't study for the GMAT. Train for it.

I solved by meaning also referring to the "that play" vs "playing" split which in my opinion can be used for PoE. But happy to hear other thoughts on this.

Researchers now regard interferon as not a single substance, but it is rather a biological family of complex molecules that play an important, though not entirely defined, role in the immune system.

The "that" modifier is working in this sentence in my opinion as noun modifier, directly referring to "complex molecules". This makes sense as it is these "complex molecules" that play an important, not entirely defined role in the immune system.

Changing this to playing an important role would in my opinion, even though very subtle, change the meaning. An -ing Modifier refers to the entire preceding clause. The preceding clause in this sentence is dealing with the fact that interferon is not a single substance but a biological family. The role of Complex molecules is however not affected by this definition of researches, it is more an additional fact that is directly linked to the noun.

For this reason, I believe that the use of a "that" modifier is more clear.

A. as not a single substance, but it is rather a biological family of complex molecules that play
B. as not a single substance but as a biological family of complex molecules playing
C. not as a single substance but as a biological family of complex molecules that play
D. not to be a single substance but rather a biological family of complex molecules playing
E. not as a single substance but instead as being a biological family of complex molecules that play

IMO C

Comma Splice. We have two independent clauses separated by a comma.

Pronoun Error. What is "it" referring to?


Between B and C:

I agree with HHPreparation 's explanation. Even if you don't know the idiom, there is a subtle difference in meaning when comparing playing vs that play.

If we simplified (B) by removing the contrast, it would read: "Researchers now regard interferon as a biological family of complex molecules playing an important, though not entirely defined, role in the immune system."

Think about that logically. Researchers regard interferon as a family of molecules playing an important role in the immune system?

No. Interferon is regarded as a family of molecules that play an important role in the immune system.



Infinitive "to be" is incorrect. The sentence begins in simple present tense "Researchers now regard..." There is no need for infinitive form.


"being" has not use in this sentence. We could remove "being" and the sentence would not change at all.

Pronoun Error. What is "it" referring to?

I was deciding between B and C and chose B because I think in C, "that play" should be "that plays" as the family is the subject.

Similar OG question. C is the correct choice and B is wrong. OA says B is wrong because subject verb agreement issue. "a Bouquet" should be the subject. I am very confused about the two questions now as the OA are applying different rules. for structures like X of Y, which should be the subject??

The artist Pierre-Auguste Renoir’s last word was “flowers,” spoken as a bouquet consisting of roses just picked from his garden were arranged in a vase on his bedroom windowsill.
• as a bouquet consisting of roses just picked from his garden were arranged
• as a bouquet of roses, just picked from his garden, were arranged
• as a bouquet of roses just picked from his garden was being arranged
• during the arrangement of a bouquet of roses, just picked from his garden
• while they arranged a bouquet of roses that had just been picked, from his garden

Researchers now regard interferon as not a single substance, but it is rather a biological family of complex molecules that play an important, though not entirely defined, role in the immune system.

A. as not a single substance, but it is rather a biological family of complex molecules that play X
B. as not a single substance but as a biological family of complex molecules playing X
C. not as a single substance but as a biological family of complex molecules that play CORRECT
D. not to be a single substance but rather a biological family of complex molecules playing
E. not as a single substance but instead as being a biological family of complex molecules that play

is the part "molecules that play" framed correctly? I had initially ruled out options preferring "playing" to "that play". Would really appreciate an explanation on why that was the wrong thing to do

I wonder, VP1030, if your explanation has got it backwards. Yes, molecules that play is perfectly fine. This sort of noun + relative clause (triggered by that or which) is quite common on the GMAT™. You can check whether the relative clause is sensible by replacing that or which with the noun it should logically refer to—here, that leaves us with molecules play an important... role in the immune system. That would be a perfect standalone sentence, so there is no problem with the relative clause.

Did you mean to say that you preferred playing to that play? Whatever the case may have been, I would suggest eliminating an option only if you are certain that something is incorrect, or that one version of the sentence achieves the same expression of meaning in a clearer or more concise way. In the question at hand, the two iterations of the sentence that use playing at the end of the underlined portion have other issues that I would consider before making a hard elimination. You can look to earlier posts in the tread for a fuller treatment of those options. In the end, you want to go with the safest option, which may not sound the best or feel right, not with the one that comes closest to what you would want to see.

Good luck with your studies.

- Andrew

Researchers now regard interferon as not a single substance, but it is rather a biological family of complex molecules that play an important, though not entirely defined, role in the immune system.
Elimination Sequence: A, D, E
A. as not a single substance, but it is rather a biological family of complex molecules that play - As not a substance but it is rather a family, is what should be the structure. Not X but Y. Additionally using another contrast word e.g. RATHER when BUT is already present is redundant. Look for other options that also use RATHER/INSTEAD with BUT. Eliminate them (i.e. D, E).
B. as not a single substance but as a biological family of complex molecules playing - In Not X but Y we must have X and Y parallel.
C. not as a single substance but as a biological family of complex molecules that play - CORRECT
D. not to be a single substance but rather a biological family of complex molecules playing -See A
E. not as a single substance but instead as being a biological family of complex molecules that play - See A

Can you please give more examples of such collective nouns which always take plural form?

Also, could you tell me if 'biological family of complex molecules that play' grammatically correct? Can you shed some light on why 'that play' refers to the complex molecules and not 'biological family' from a grammar point of view?

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