GMAC Practice Test 2: SC

[sarora]

Although the turtle has been toothless for more than 150 million years, in some contemporary turtle species the moderately sharp and jagged edges of their horny jaws function for teeth.

1) their horny jaws function for teeth
2) its horny jaws function for teeth
3) its horny jaws function as do teeth
4) the horny jaws function as teeth do
5) the horny jaws function as teeth

GMAC : 5) totally does away with the possessive pronoun and places an article(?)
Me: 2)

[RonPurewal]

The possessive pronoun actually NEEDS to be done away with, as it has no proper antecedent. The best approximation to an antecedent is 'the turtle,' but that doesn't work because, as used here, 'the turtle' refers to the entire range of turtle species throughout evolutionary history - not just the 'contemporary turtle species' described in the latter part of the sentence.

In any case, the context here makes the possessive unnecessary. Same deal with the following shorter (and easier-to-examine) sentence: In humans, who walk upright, THE spinal cord is perhaps still better adapted to its historical horizontal position.

[Andrea]

What is the difference between D and E
I chose D because the horney jaws function as teeth do, making the two verbs to be parallel

[Guest]

Although the turtle has been toothless for more than 150 million years, in some contemporary turtle species the moderately sharp and jagged edges of their horny jaws function for teeth.

1) their horny jaws function for teeth
2) its horny jaws function for teeth
3) its horny jaws function as do teeth
4) the horny jaws function as teeth do
5) the horny jaws function as teeth

GMAC : 5) totally does away with the possessive pronoun and places an article(?)
Me: 2)

Answer should be E. A,B, and C all have possessive pronouns without referring to any possessive noun. Answer choice D is awkward and incorrect, because it ends with "do". Thus we are left with E, which is correct.

[RonPurewal]

What is the difference between D and E
I chose D because the horney jaws function as teeth do, making the two verbs to be parallel

but that's not what the sentence means.
the intended meaning is that the horny jaws play the role of teeth, which is the correct interpretation of 'function as teeth'.
i.e.,
function as teeth --> they work as an acceptable substitute for teeth
function as teeth do --> they work in the same way as teeth do - same mechanics, same action, etc. this is not what is meant.

[herogmat]

The possessive pronoun actually NEEDS to be done away with, as it has no proper antecedent. The best approximation to an antecedent is 'the turtle,' but that doesn't work because, as used here, 'the turtle' refers to the entire range of turtle species throughout evolutionary history - not just the 'contemporary turtle species' described in the latter part of the sentence.

In any case, the context here makes the possessive unnecessary. Same deal with the following shorter (and easier-to-examine) sentence: In humans, who walk upright, THE spinal cord is perhaps still better adapted to its historical horizontal position.

Sorry for bumping in an old thread ... Ron , can you please explain why 'contemporary turtle species' can't be the antecedent of the pronoun 'their'?

[Ben Ku]

Ron , can you please explain why 'contemporary turtle species' can't be the antecedent of the pronoun 'their'?

"In some contemporary turtle species" is an adverbial modifier of the verb "function" and is not part of the main subject of the sentence, and cannot serve as the antecedent for "their."

[herogmat]

Ron , can you please explain why 'contemporary turtle species' can't be the antecedent of the pronoun 'their'?

"In some contemporary turtle species" is an adverbial modifier of the verb "function" and is not part of the main subject of the sentence, and cannot serve as the antecedent for "their."

Thanks Ben. Still I am not able to get hold of the sentence structure quite clearly. Do you have any other example of adverbial modifier modifying a verb at later part of the sentence? I was just wondering if the modifier could modify "Although the turtle has been toothless for more than 150 million years".

[jessie-cn2007]

Ron , can you please explain why 'contemporary turtle species' can't be the antecedent of the pronoun 'their'?

"In some contemporary turtle species" is an adverbial modifier of the verb "function" and is not part of the main subject of the sentence, and cannot serve as the antecedent for "their."

Hi Ben,
I am confused. Only the subject or object can serve as the antecedent of a pronoun？
Can't they refers to 'contemporary turtle species' , in stead of the whole adverbial modifier?
Thank you~

[igordudchenko]

I disqualified A because of incorrect idiom 'function for'. The correct idiom is 'function as'.

I was hesitating between D and E, but when I recalled that correct comparison is 'X as Y' (if I am not mistaken, in SC book the example is 'nowadays mobile phones often act as cameras'.

Ron, on the real test, will we ALWAYS see the second verb when an actioon quality is compared, i.e.:
Joshua swims as fast as Bill does?
Can
Joshus swims as fast as Bill
be a correct answer?

[tim]

i think the more important issue to be aware of is that the GMAT will probably not require you to choose between the two options you have given. both are sufficiently plausible as to make it a judgment call which to use. as a result, you should look elsewhere in the answer choices to see what else you can identify as a difference between those two choices and make your decision based on that distinction instead..

[rachelhong2012]

What is the difference between D and E
I chose D because the horney jaws function as teeth do, making the two verbs to be parallel

but that's not what the sentence means.
the intended meaning is that the horny jaws play the role of teeth, which is the correct interpretation of 'function as teeth'.
i.e.,
function as teeth --> they work as an acceptable substitute for teeth
function as teeth do --> they work in the same way as teeth do - same mechanics, same action, etc. this is not what is meant.

What exactly is the role of helping verb in any sentence? I feel that they usually show up in comparison cases, do they have any other usage?

Thanks!

[RonPurewal]

hi,

What exactly is the role of helping verb in any sentence?

rachel, if you have a question this general, your best bet is to call on the wisdom of the internet: just type "helping verbs english" (or other such search term) into your favorite search engine, and start reading the results. for any question as wide-ranging as this one, we won't be able to do justice to the topic in the space of a forum post.

however, i will point out that the whole "helping verbs are limited to comparisons" idea is incorrect. for instance, if i say I can swim, the helping verb "can" plays an essential role; this sentence is not a comparison.

once you've done some basic research, we will be glad to answer more specific questions if you have them.

[kiranck007]

Although the turtle has been toothless for more than 150 million years, in some contemporary turtle species the moderately sharp and jagged edges of their horny jaws function for teeth.

1) their horny jaws function for teeth
2) its horny jaws function for teeth
3) its horny jaws function as do teeth
4) the horny jaws function as teeth do
5) the horny jaws function as teeth

GMAC : 5) totally does away with the possessive pronoun and places an article(?)
Me: 2)

I arrived at 5 but with a different approach; please correct if I am wrong.
Prepositional phrases ->
"in some contemporary turtle species"

Subject-> "The moderately sharp and jagged edges"
Verb -> function

[jlucero]

Although the turtle has been toothless for more than 150 million years, in some contemporary turtle species the moderately sharp and jagged edges of their horny jaws function for teeth.

1) their horny jaws function for teeth
2) its horny jaws function for teeth
3) its horny jaws function as do teeth
4) the horny jaws function as teeth do
5) the horny jaws function as teeth

GMAC : 5) totally does away with the possessive pronoun and places an article(?)
Me: 2)

I arrived at 5 but with a different approach; please correct if I am wrong.
Prepositional phrases ->
"in some contemporary turtle species"

Subject-> "The moderately sharp and jagged edges"
Verb -> function

Since all 5 answer choices have "function" as the verb, I'm not sure how you eliminated the other 4. But if you meant to use the idiom "The edges function AS TEETH", yes, this would be a good way of looking at it.