A. the brain growing in mice when placed in a stimulating environment or neurons increasing in canaries that
Incorrect

B. mice whose brains grow when they are placed in a stimulating environment or canaries whose neurons increase when they
Mice or brains? Could be clearer so we'll put "maybe" if there's no better answer.

C. mice's brains that grow when they are placed in a stimulating environment or canaries' neurons that increase when they
Neurons don't learn new songs

D. the brain growth in mice when placed in a stimulating environment or the increase in canaries' neurons when they
Same as C

E. brain growth in mice that are placed in a stimulating environment or an increase in neurons in canaries that
Best answer

dear GMAT Ninja
I got this wrong. But, after that I find the use of WHEN is incorrect in all the first four options. Will it be deterministic error or can we really eliminate all 4 on the basis of wrong use of WHEN.

No, a wrong answer cannot be eliminated because of use of "when".

Option D is eliminated not because "when" is used, but because parallelism is lost.

In option D, "when placed in a stimulating environment" comprises of a participle ("placed"), whereas "when they learn new songs" comprises of a clause. D would be better if the last part were as follows: "when learning new songs" (participle instead of clause.)

Moreover "increase in Neurons IN CANARIES" in E (rather than "increase in canaries' neurons)" in D goes better with "brain growth IN MICE"

Another problem with D is that the subject pronoun "they" refers to the possessive antecedent "canaries' "

I had a theory in mind when I was solving this question.
Complex gerunds can be parallel with action nouns only, and not with simple gerunds or concrete nouns. Examples of production of brain cells qualifies as action noun, and therefore can be parallel with a complex gerund or action noun only.
Does the answer satisfy the above theory?
DmitryFarber ChrisLele egmat sayantanc2k daagh

A- include the brain growing is incorrect
B- when they are-they is ambiguous- mice and brains
c- again they is ambiguous
D- when placed is incorrect- it can refer to brain or mice
E-Correct

I'm skeptical of the use of "when" in this problem. Formally, "when" is used as a conjunction or adverb. Informally, "when" can be used as a relative pronoun in place of "at which" or "during which" (see here).

If "when" is perceived as a conjunction, then the original sentence might read like this: "When placed in a stimulating environment, recently documented examples of neurogenesis, the production of new brain cells, include the brain growing in mice". This clearly is not what we want.

If "when" is perceived as a relative pronoun, then according to the Cambridge Dictionary it isn't fulfilling its function of replacing "at which" or "during which". And thus, it's being used in some way that most grammar authorities don't agree is acceptable even for informal usage.

These concerns are important to note, but probably not enough to eliminate the options that use "when". GMAT can sometimes use language that is more informal than most grammar authorities agree is acceptable.

A more important concern is that if we assume "when" is being used as a relative pronoun, then which noun is "when" modifying? In (A) "when" could be modifying "brain growing" or "mice". We don't know because there is no verb to tell us like there is when using "that" ("that are" in (E) indicates we are modifying "mice" and not "brain growth").

Finally, in option (E) both examples use "that" rather than one using "when" and the other using "that". This creates mild parallelism that probably isn't enough to tip the scale in favor of (E) by itself but it's a nice bonus and we can feel better about choosing (E).

Adding on to the discussion:

Can we not eliminate (A) & (C) by looking at the fact that the 'when' [relative clause modifier] doesn't have a 'subordinate verb'?

If you look at the first part (A/C):
The brain growing/The brain growth in mice[prep phrase]when placed [verb-ed modifier] in a stimulating environment [prep phrase] -- the when relative clause is modifying the brain growing/the brain growth but the clause doesn't have a verb, since 'placed' is a modifier

we need 2 examples of the PRODUCTION of new brain cells.

B/
mice and canaries are not examples of the PRODUCTION of brain cells.

C/
mice's brains and canaries' neurons are not examples of the PRODUCTION of brain cells (rather, they are examples of the brains or brain cells themselves).

... as opposed to the correct answer
E/
brain growth and an increase in neurons absolutely ARE examples of the PRODUCTION of new brain cells.
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In option (E), the presence of the extra 'an' does not make the two phrases parallel. Can you please shed more light on that?
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Hi Jay, when looking for parallelism, we should not look at word on word similarity; for example, in option E, the presence of an in one phrase does not necessitate the presence of an in the other phrase.

The structure of option E is:

...include brain growth in mice ...or an increase in neurons...

Both the bold parts are Noun-phrases, and hence parallel.
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hi experts,

1. my doubt is can a modifier ( when placed) be parallel to clause ( when they learn ) as in option D . ( i eliminated D because of that ), can i do that.


JonShukhrat,

2.

2.a)a doubt posted by a user above, i want experts to confirm the above also because, the so called action noun is outside our parallell conflict ( as that is noun which includes x or Y), . whether this should be considered as well ..





slayer1983

thanks

So here the sentence really wants to say that the canaries are learning the new song? and not the mice?

Pleaaasee Help!

Recently documented examples of neurogenesis,
the production of new brain cells, - This is an appositive phrase.
include
the brain growing in mice when placed in a stimulating environment – This is the first element in the parallel list.
or neurons increasing in canaries that learn new songs. – This is the second element in the parallel list.


(A) the brain growing in mice when placed in a stimulating environment or neurons increasing in canaries that

The list if not parallel. Also the brain growing in mice – not as elegant to say. Also neurons are not increasing. The number of neurons are increasing.
(B) mice whose brains grow when they are placed in a stimulating environment or canaries whose neurons increase when they
Here examples are the mice and canaries – This is the change in meaning of the sentence

(C) mice's brains that grow when they are placed in a stimulating environment or canaries' neurons that increase when they
It is unclear what they refers to in this choice

(D) the brain growth in mice when placed in a stimulating environment or the increase in canaries' neurons when they

It is unclear what they refers to in this choice
(E) brain growth in mice that are placed in a stimulating environment or an increase in neurons in canaries that
This choice is a clear winner.

egmat
I chose E for all the correct reasons.
My query is of "that " and "those" which one is correct?

I think since its a mice & cranaries "those" is the correct usage. Kindly explain.

Clearly that

Here is a post by GMATNinja on usage of 'that'

https://gmatclub.com/forum/experts-topi ... l#p1879038

E. brain growth in mice s that are placed in a stimulating environment or an increase in neurons in canaries that

If it is plural, why mice is in the singular?
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Hello plaverbach,

The singular of mice is mouse , there is not a plural for mice because it is already in the plural form.

egmat

in option D, why "they" can't refer to canaries? As we have seen in many examples that a pronoun can refer to a possessive noun.

Hello sid0791,
I think it is because canaries here act as an adjective and not a noun, so they cannot refer to an adjective.