Normally a bone becomes fossilized through the action of groundwater

Hello Everyone!

We’ve got a list. parallelism! Any time you see a list on the exam, that means there will be a few unparallel options that you’ll be able to quickly dump, and that will help us get to the right option even faster.

So what could the parallel structure be here?

Permeates, washes, and replaces
-or-
Permeating, washing, and replacing (but there are some problems with this one...more to come on that later)

Let’s see how each answer holds up:

(A) which permeates the bone, washes away its organic components, and replaces them → CORRECT
(B) which permeates the bone, washes away its organic components, and those are replaced → INCORRECT
(C) which permeates the bone, washing away its organic components, to be replaced → INCORRECT
(D) permeating the bone, washing away its organic components, to be replaced → INCORRECT

(E) permeating the bone, washing away its organic components and replacing them → INCORRECT

So why else is option E incorrect, even though it uses parallel structure? The GMAT requires the use of the serial comma (aka the Oxford comma) for every item in a list, including the last item in a list of 3+ items. Answer E doesn’t use a serial comma for the third item, so it’s wrong.

But even more fundamentally, (options D and E), insert “permeating” as an -ing modifier right after the comma, which opens up a confusing ambiguous reference because “permeating” could mean that:

1) groundwater permeates the bone
2) the action of groundwater permeates the bone
3) or even the fossilization through the action of groundwater permeates the bone

A is both parallel, and retains the intended message.

Don’t study for the GMAT. Train for it.
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Dear Friends,

Here is a detailed explanation to this question-

Meaning is crucial to solving this problem:
Understanding the intended meaning of the sentence is key to solving this question; the intended meaning is that normally a bone becomes fossilized through the action of groundwater, and the groundwater permeates the bone, washes away its organic components, and replaces these components with minerals.

Concepts tested here: Meaning + Verb Forms + Parallelism

• All elements in a list must be parallel.
• The introduction of the present participle ("verb+ing") after the comma generally leads to a cause-effect relationship.
• The infinitive verb form (“to + base form of verb”) is the preferred construction for referring to the purpose/intent of an action.
• The “comma + and” (oxford comma) construction is used to join the last element of a list of more than two other elements.

A: Correct. This answer choice uses the phrases “which permeates the bone”, “(which) washes away its organic components”, and “(which) replaces them with minerals”, conveying the intended meaning – that normally a bone becomes fossilized through the action of groundwater, and the groundwater permeates the bone, washes away its organic components and replaces those components with minerals. Further, Option A correctly uses the “comma + and” (oxford comma) construction to join the last element of a list of more than two other elements. Additionally, Option A maintains parallelism among “permeates the bone”, “washes away its organic components”, and “replaces them with minerals”.

B: This answer choice fails to maintain parallelism among “permeates the bone”, “washes away its organic components”, and “those are replaced with minerals”; please remember, all elements in a list must be parallel.

C: This answer choice alters the meaning of the sentence through the phrase “washing away its organic components”; the use of the “comma + present participle (“verb+ing” – “washing” in this sentence) incorrectly implies that groundwater permeates the bone, and as a result, washes away its organic components; the intended meaning is that that groundwater permeates the bone, and as a separate action, washes away its organic components; please remember, the introduction of the present participle ("verb+ing"- “washing” in this case) after comma generally leads to a cause-effect relationship. Moreover, Option C further alters the meaning of the sentence through the phrase “to be replaced”; the use of the infinitive verb form (“to + base form of verb” – “to + be” in this case) incorrectly implies that groundwater permeates the bone and washes away its organic components in order to be replaced itself with minerals; the intended meaning is that groundwater permeates the bone and washes away its organic components, and as a separate action replaces those components with minerals; please remember, the infinitive verb form (“to + base form of verb”) is the preferred construction for referring to the purpose/intent of an action.

D: This answer choice alters the meaning of the sentence through the phrases “permeating the bone” and “washing away its organic components”; the use of the “comma + present participle (“verb+ing” – “permeating” and “washing” in this sentence) illogically implies that normally a bone becomes fossilized through the action of groundwater, and, as a result, the bone permeates itself and washes away its own organic components; the intended meaning is that normally a bone becomes fossilized through the action of groundwater, and the groundwater permeates the bone and washes away its organic components; please remember, the introduction of present participle ("verb+ing"- “permeating” and “washing” in this case) after comma generally leads to a cause-effect relationship. Moreover, Option D further alters the meaning of the sentence through the phrase “to be replaced”; the use of the infinitive verb form (“to + base form of verb” – “to + be” in this case) incorrectly implies that groundwater permeates the bone and washes away its organic components in order to be replaced itself with minerals; the intended meaning is that groundwater permeates the bone and washes away its organic components, and as a separate action replaces those components with minerals; please remember, the infinitive verb form (“to + base form of verb”) is the preferred construction for referring to the purpose/intent of an action.

E: This answer choice alters the meaning of the sentence through the phrases “permeating the bone”, “washing away its organic components”, and “replacing them with minerals”; the use of the “comma + present participle (“verb+ing” – “permeating”, “washing”, and “replacing” in this sentence) illogically implies that normally a bone becomes fossilized through the action of groundwater, and, as a result, the bone permeates itself, washes away its own organic components, and replaces those components with minerals; the intended meaning is that normally a bone becomes fossilized through the action of groundwater, and, and the groundwater permeates the bone, washes away its organic components, and replaces those components with minerals; please remember, the introduction of the present participle ("verb+ing"- “permeating”, “washing”, and "replacing" in this case) after comma generally leads to a cause-effect relationship. Further, Option E incorrectly uses conjunction (“and” in this case) to join the final element in a list of more than two elements; please remember, the “comma + and” (oxford comma) construction is used to join the last element of a list of more than two other elements.

Hence, A is the best answer choice.

To understand the concept of "Comma Plus Present Participle for Cause-Effect Relationship" on GMAT, you may want to watch the following video (~3 minutes):



To understand the concept of "Oxford Comma", you may want to watch the following video (~3 minutes):



All the best!
Experts' Global Team
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chetan2u
In option A...what is antecedent of pronoun 'them'?

Posted from my mobile device

The underlined portion talks of three actions ..
I) permeates the bone
II) washes away it's organic components
III)) replaces them..

Who does this action - the ground water

Normally becomes fossilized through the action of groundwater, which permeates the bone, washes away its organic components, and replaces them with minerals.


A. which permeates the bone, washes away its organic components, and replaces them
Correct... The ground water, which permeates..., Washes..... And replaces...

B. which permeates the bone, washes away its organic components, and those are replaced
THOSE is wrong and is not parallel with other two actions

C. which permeates the bone, washing away its organic components, to be replaced
This makes the parallel actions as WASHING... dependent on the previous phrase

D. permeating the bone, washing away its organic components, to be replaced
changes the actions as MODIFIER

E. permeating the bone, washing away its organic components and replacing them
Same as D

A

NEW question from GMAT® Official Guide 2019

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Going by meaning.

Intended meaning is - a bone becomes fossilized through the action of groundwater. It is ground water that does three things
1) permeates the bone,
2) washes away its organic components
3) and replaces them with minerals.

This is conveying correct meaning as well.

A. which permeates the bone, washes away its organic components, and replaces them. A is correct

B. which permeates the bone, washes away its organic components, and those are replaced those are replaced - makes it wrong

C. which permeates the bone, washing away its organic components, to be replaced it changes the second item in list to modifier. And this modifier is placed next to relative clause. Hence doesn't convey intended meaning.

D. permeating the bone, washing away its organic components, to be replaced It uses two modifier placed next to each other. But it should be modifying groundwater. This modifier should be connected with "and". This is incorrect.

E. permeating the bone, washing away its organic components and replacing them Similar error as in D.

Clearly A is the Ans

Normally a bone becomes fossilized through the action of groundwater, which permeates the bone, washes away its organic components, and replaces them with minerals.


A. which permeates the bone, washes away its organic components and replaces them --- correct choice.

B. which permeates the bone, washes away its organic components, and those are replaced--- and 'those are replaced' breaks the //ism.

C. which permeates the bone, washing away its organic components, to be replaced --- There is no intention involved in this action. This is a natural phenomenon. Hence, 'to be replaced' is out of context.

D. permeating the bone, washing away its organic components, to be replaced -- 'comma +permeating' changes the meaning, since permeating does not now modify the groundwater.

E. permeating the bone, washing away its organic components and replacing them ---- same error as in D.



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them refers to organic components

In answer choice A,they are talking about "them" which refers to singular noun "a bone".How it could be correct ?

"them" is for organic components, not for "a bone".

egmat

First glance A is perfect. Is there a trap? Delving into it deeper marked E.

Why is E incorrect?

If a comma+a Verb-ing modifier can modifiy the how aspect of the action presented before, the comma+Verb-ing modifier presents how the bone gets fossilized by the action of ground water and mantains the parallel structure too?

What am I missing?

Posted from my mobile device

benignfiend

if groundwater is the subject,then verb"ing" will make some sense to the sentence...

hope it helps

But that doesnt answer my query. Request GMATNinja sudarshan22 aragonn to please step in

singh8891 - GMAT is not about the best answer. It about finding an option that is best of the lot. As in this case A is. Other posts have covered all options, lets focus on use of them. its pronoun, it has to point nearest noun that too plural. Let see the possibilities. 'organic components' is the only possible contender. so them refers to it without a doubt. I see you raised this doubt on grounds that "Since the three actions are independent and do not have a causal relationship". Well, to be start these three are parallel. yet this has nothing to do with why them refer to organic components. So my 2 cents are, if you need to find the antecedent of a pronoun, look for nearest noun, if you find multiple possibilities, then only be skeptical about its use. Hope its helpful.
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Q) Normally a bone becomes fossilized through the action of groundwater ________ with minerals.

A) which permeates the bone, washes away its organic components, and replaces them

B) which permeates the bone, washes away its organic components, and those are replaces

C) which permeates the bone, washing away its organic components, to be replaced

D) permeating the bone, washing away its organic components, to be replaced

E) permeating the bone, washing away its organic components and replacing them

Correct answer( according the the guide ): A

But we are talking about a bone here which is singular and the first options says ' and replaces them ' so how can that be correct when in the same sentence it states ' washing away its organic components' which addresses the bone as singular.

Posted from my mobile device

First you should understand the meaning of the sentence. It is saying that 'normally' (there could be other ways too) a bone becomes fossilized through the action of ground water. There are three ways, which happen in sequence one after another, in which the ground water fossilizes a bone.

A. (Correct) Here the noun modifier 'which' shows the three ways in which ground water fossilizes a bone. Some of you might not realize what 'them' replaces. The only plural noun is 'organic components'. Hence this is correct and unambiguous.

B. Like in option A, it shows three ways in which ground water fossilizes a bone. However, those three elements are not parallel. The first two elements 'permeates', 'washes' are verbs whereas 'those are replaced' is a clause. When a modifier begins with to be [verb], it modifies the entire preceding clause, similar to a comma –ing modifier.

C. three elements are not parallel like in A and B even though these are still the three ways in which ground water fossilizes a bone. 'to be replaced' denotes that replacing with minerals is the purpose of a bone becoming fossilized, which is wrong.

D. comma-ing such as 'premeating' and 'washing' should modify the main clause. However, the verb of the main clause is 'becomes'. comma-ing either provide the consequence of the main verb of the main clause or provides 'HOW' aspect of that verb. It is neither here. These elements describe how the ground water fossilizes a bone, not how normally a bone becomes fossilizes.

E. Like in D, these three elements should describe how 'ground water' fossilizes a bone, not how in general a bone becomes fossilizes. It lists three elements but the third element is not even separated by an Oxford comma.

What is "them" in (A)? Isn't a Subject-Verb agreement problem?

them correctly refers to organic components. In fact, organic components is pretty much the only eligible antecedent of them.


Might be handy to remember that any incorrect usage of them would be a pronoun issue rather than a subject-verb agreement issue. This is because them is neither a subject nor a verb; it's an object pronoun.
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GMATNinja How is E here incorrect? I am unable to understand how option E is altering the meaning ?

Isn't 'them' in option A ambiguous?
In parallelism, all three are supposed to be parallel. How is third one referring to the second one?
Please help!