Botanists have proven that if plants extended

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Botanists have proven that if plants extended laterally beyond the scope
of their root system, they will grow slower than do
those that are more
vertically contained.

A:...
B: extended laterally beyond the scope of their root system, they will grow
slower than
C: extend laterally beyond the scope of their root system, they grow more slowly
than
D: extend laterally beyond the scope of their root system, they would have
grown more slowly than do
E: extend laterally beyond the scope of their root system, they will grow more
slowly than do

I don't understand what is happening here; i used "If X happens (then) Y
will happen" but failed. I need further explanation.

OA is C
Source: — Sentence Correction |

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by reply2spg » Mon Sep 13, 2010 11:47 am
What is wrong with E?
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by Gurpinder » Mon Sep 13, 2010 12:09 pm
reply2spg wrote:What is wrong with E?
Its suggesting a definitive by using "will" whereas the sentence is an "IF" clause.

(C) is good.
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by karanrulz4ever » Mon Sep 13, 2010 12:28 pm
E is wrong for two reasons according to me:
1) Comparisons: X has more money than Y - Correct.
X has more money than does Y - Incorrect.
2) If is followed by past tense(extended). Hence will/can cannot be used.

Hence C

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by uwhusky » Mon Sep 13, 2010 12:33 pm
I guess the focus here is trying to teach the students to avoid using helping verb when the comparison isn't ambiguous. However, I do agree that the modal verb "will" should be in the correct sentence following "if...+ present tense verb".
Yep.

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by e-GMAT » Mon Sep 13, 2010 1:28 pm
Lets focus on choices C and E.

Botanists have proven that if plants extended laterally beyond the scope of their root system, they will grow slower than do those that are more vertically contained.

Meaning = Botanists have proven a certain fact. This fact is stated in the if..then construction.

Now clearly as you all notes, past tense in if clause cannot be used with future tense in then clause. So this makes Choice A incorrect.

Choice E:
extend laterally beyond the scope of their root system, they will grow more slowly than do
This choice is grammatically correct, except two things:
1: Tenses used in if..then construction are not appropriate to communicate the intended meaning. As we noted above, the botanists have proven something - they have proven a fact. This fact is true in present context and is communicated using simple present tense in both if and then clauses. In this choice, thus, use of simple future tense is inappropriate {this combination (simple present with simple future in if..then) is used to express an event that will certainly take place in future}.

Lets consider an example that we use in our concept file for Conditional Verb.
If the family goes out for dinner, they dine at Macaroni Grill - This sentence states a fact.
If the family goes out for dinner, they will dine at Macaroni Grill - This sentence states an event that will certainly take place in future if the condition is met.

Thus, both sentences above are grammatically correct but they communicate different meaning.

Choice E would be correct if the non-underlined portion were worded as follows:
Botanists have done some changes to their experimental plants such that if these plants extend laterally beyond the scope of their root system, they will grow slower than those that are more vertically contained.

Now this sentence shows what will happen in future based on the changes implemented by the botanists.

So as I always say, understand the context of the sentence and then pick the correct answer.

2: Use of do - I have not seen an OG question that uses presence of correct helping verb as the error to eliminate an answer choice. Yes, in this sentence, "do" is not required since the comparison is clear, but IMO, this is not an error based on which elimination can be done.

I hope this explains why Choice C is the correct answer.

For e-gmat users, these concepts of if..then constructions are taught in the advanced error concept file titled - Conditional Verb.

Thanks,

Payal Tandon

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by uwhusky » Mon Sep 13, 2010 1:38 pm
Thank you Payal for the clarification. I have completely ignored the difference in if...then constructions.
Yep.

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