Sentence Correction

Reptiles, by drawing their body heat directly from the Sun rather than burning calories to generate it, can survive on ten percent of the nourishment that a mammal of similar size would normally require.

A) rather than burning calories to generate it
B) rather than the generation of body heat by burning calories
C) and not from generating it by burning calories
D) instead of by burning calories for generating it
E) instead of body heat generated by burning calories

Apparently A is the correct answer, but I have hard time figuring it out.

According to me, the correct option should have been:

rather than by burning calories to generate it

Since A does not use "from", it's difficult to figure out whether the preposition should be "from" or "by".

Can an expert please help.

by drawing... rather than... [by] burning

A) we don't have to repeat by
B)by drawing... rather than... the generation
Not parallel
C) and not from generating...not parallel
D) instead of by does not sound right.
E) It changes meaning. Body heat is a new term here. Eliminate.

So the answer is A

Thanks, as I had stated, A can be interpreted as:

Reptiles, by drawing their body heat directly from the Sun rather from than burning calories to generate it, can survive on ten percent of the nourishment that a mammal of similar size would normally require.

To me, this also sounds a logical interpretation. In other words, Reptiles draw their body heat directly from
a) Sun and not form
b) Burning calories

What's wrong with this interpretation?

iongmat wrote:Thanks, as I had stated, A can be interpreted as:

Reptiles, by drawing their body heat directly from the Sun rather from than burning calories to generate it, can survive on ten percent of the nourishment that a mammal of similar size would normally require.

To me, this also sounds a logical interpretation. In other words, Reptiles draw their body heat directly from
a) Sun and not form
b) Burning calories

What's wrong with this interpretation?

In the OA, it refers to their body heat.
The interpretation above implies that reptiles are doing the following:
drawing their body heat directly from the sun rather than drawing their body heat from burning calories to generate their body heat.
The portion in red makes no sense.
The only viable interpretation is that reptiles prefer one METHOD of surviving (drawing) to ANOTHER (burning).
How can reptiles survive on so little nourishment?
by DRAWING their body heat directly from the sun rather than [by] BURNING calories to generate their body heat.
The preposition in brackets is omitted, but its presence is understood.
It is very common to omit a preposition after rather than.

Thanks a lot Mitch. This totally clears it up.

And it also answers why "to generate it" is required here; else sentence might indeed have been ambiguous (the way I interpreted it).

Hi Mitch, may I ask why choice D is wrong?

My consideration is to choose a better parallelism from A and D. For me, "By doing instead of by doing is very clear."

Thank you in advance.

annays wrote:Hi Mitch, may I ask why choice D is wrong?

My consideration is to choose a better parallelism from A and D. For me, "By doing instead of by doing is very clear."

Thank you in advance.

A preposition must be followed by a NOUN serving as the OBJECT of the preposition.
Since instead of is a preposition, it may not be followed by a modifier such as by burning.

Thank you Mitch!

Anna

How can one defend answer (A) as grammatically proper? It may be a better choice than any of the others, but nevertheless it translates to "Reptiles, by drawing their body heat directly from the Sun rather than burning calories to generate the Sun...," which is nonsense. Am I missing something?

Gee Matt wrote:How can one defend answer (A) as grammatically proper? It may be a better choice than any of the others, but nevertheless it translates to "Reptiles, by drawing their body heat directly from the Sun rather than burning calories to generate the Sun...," which is nonsense. Am I missing something?

OA: by drawing their body heat directly from the Sun rather than burning calories to generate it
Here, it serves to refer to their body heat.
Conveyed meaning:
by drawing their body heat directly from the Sun rather than burning calories to generate their body heat
This meaning is wholly logical.

I can see that, but seems like sloppy question writing by the exam writers.

Gee Matt wrote:I can see that, but seems like sloppy question writing by the exam writers.

There is no ambiguity -- or sloppiness -- in the OA.
Generally, rather than serves to connect PARALLEL FORMS.
Parallel forms must serve the SAME FUNCTION.
by drawing their body heat directly from the Sun rather than burning calories to generate it
Here, the pronoun in the blue phrase -- it -- is the direct object of a verb form (to generate).
Thus, the referent for it is clearly the preceding direct object in the red phrase (their body heat, the direct object of drawing).

In contrast:
by traveling away from the Sun rather than toward it
Here, the pronoun in the blue phrase -- it -- is the object of a preposition (toward).
Thus, the referent for it is clearly the preceding object of a preposition in the red phrase (the Sun, object of the preposition away from).

Very helpful. Thank you.

It is still not clear to me why exactly the preposition "by" does not have to be repeated to make the sentence parallel.

by X rather than by Y.

So,

BY drawing their body heat directly from the Sun rather than BY burning calories to generate it.

Can somebody please clarify?

bobbyf wrote:It is still not clear to me why exactly the preposition "by" does not have to be repeated to make the sentence parallel.

by X rather than by Y.

So,

BY drawing their body heat directly from the Sun rather than BY burning calories to generate it.

Can somebody please clarify?

SEESAW conjunctions -- either X or Y, not X but Y, etc. -- must be carefully balanced.
either FROM John or FROM Mary
not BY this week but BY next week.
Here, the prepositions in blue MUST be included to yield the required balance.

rather than does not constitute a seesaw conjunction and thus does not have to satisfy this constraint.
OA: by drawing their body heat directly from the Sun rather than burning calories to generate it
Here, it is NOT necessary to repeat by after rather than.