Doctors hope that one day the body’s master cells, called stem cells,

Question

Doctors hope that one day the body’s master cells, called stem cells, can be directed to grow in organs or tissues appropriate for  transplant, use them to test drugs and potentially toxic chemicals, and may study them  to gain insight into basic human biology.

(A) transplant, use them to test drugs and potentially toxic chemicals, and may study them

(B) transplant, using them to test drugs and potentially toxic chemicals, and studied

(C) transplant, used to test drugs and potentially toxic chemicals, and studied

(D) a transplant, use them for testing drugs and potentially toxic chemicals, and for studying

(E) a transplant, used to test drugs and potentially toxic chemicals,and may study them

KyleWiddison · Accepted Answer

The OA is C. Choice B is tempting because it's essentially grammatically correct with directed/studied are parallel with a modifying phrase sandwiched in between (you could argue pronoun ambiguity but the GMAT accepts ambiguity in many cases). You have to decide between B & C on the basis of meaning. Let's look at the structures of both options:

Option B 
Doctors hope stem cells can be
directed for transplant, using them (transplants?) to test drugs/chemicals,
and
studied to gain insight

Option C 
Doctors hope stem cells can be
directed for transplant, 
used to test drugs/chemicals,
and
studied to gain insight

Option B is eliminated for questionable/illogical meaning. Option C wins.

KW

Marcab · Answer

A clear C. Can be directed, can be used and can be studied.
One thing that I learnt from this is that GMAT can so traumatize you that rather than finding the simple parallelism, you would go for an adverbial effect modifier.

Took 2.04 mins when it should have been down under a minute.
Well you continue learning until the last minute of the match.

Took 2.04 mins when it should have been down under a minute. Well you continue learning until the last minute of the match.

CrackverbalGMAT · Answer

This question is based on Parallelism.

The underlined portion of the sentence is part of a list of things that the doctors hope the master cells can be used to do. The first item in the list is “directed to grow…”. So, the other items in the list must be parallel to the first –  directed to….used to…..studied to…
 
Since the subject ‘the body’s master cells’ is mentioned, there is no need for a pronoun to be added to the list. So, the pronoun ‘them’ is redundant.

In Option A, the verbs ‘use’ and ‘may study’ are not parallel to ‘directed’. All three verbs must follow the auxiliary verb ‘can be’. The present form ‘use’ and the verb ‘may study’ cannot be used after ‘can be’. So, Option A can be ruled out.

In Option B, ‘using’ is not parallel to ‘directed’. Because the verb ‘studied’ is parallel to ‘directed’, this seems to be a viable option with a modifying phrase in between. However, the modifying phrase “using them to test drugs and potentially toxic chemicals” would modify “the body’s master cells”. This would make the sentence illogical since the meaning conveyed is that the master cells would use them to test drugs and potentially toxic chemicals. The antecedent of the pronoun ‘them’ is not clear. So, Option B can be ruled out.

In Option C, the parallelism has been maintained. The verbs ‘used’ and ‘studied’ are parallel to ‘directed’. This is also the most concise option. So, C is the best of all the options.

In Option D, the verb ‘use’ and the participle ‘studying’ are not parallel to ‘directed’. So, Option D can also be ruled out.

In Option E, ‘may study’ is not parallel to ‘directed’. So, Option E can also be ruled out.

Therefore, C is the most appropriate option.

Jayanthi Kumar.

alpha_plus_gamma · Answer

C for me, can be directed, used, and studied

Legend · Answer

If we break down this sentence, we see that Doctors hope that  the body's master cells can be

1. (the body's master cells can be) directed to grow in organs 
2. (the body's master cells can be) used to test drugs and potentially toxic chemicals
3. and (the body's master cells can be) studied

Doctors hope for these three things. The first one is outside the underlined part and will dictate the parallel structure the other two will take. In order to keep a parallel structure and consistencey among these three thing, we need to pick answer  choice C .

mikeCoolBoy · Answer

I'm going with C in this one. 
There are two possible parallelism points here hope that ... and master cells can be. None of the options include that, so I think that we should try to find parallelism in the rest of the sentence.

Doctors  hope that  one day the body’s master cells  can be

(A) master cells  can be directed  to grow in organs or tissues appropriate for transplant, use them to test drugs and potentially toxic chemicals, and may study them to gain insight into basic human biology

this sentence suggests that the master cells use themselves to test drugs out.

(B) master cells  can be directed  to grow in organs or tissues appropriate for transplant, using them to test drugs and potentially toxic
chemicals, and studied.

using and studied are not parallel

C. master cells  can be directed  to grow in organs or tissues appropriate for transplant,  used to test drugs and potentially toxic chemicals, and   studied.
I think that this is the correct answer choice. the three elements are parallel.

D. a transplant, use them for testing drugs and potentially toxic chemicals, and for studying.

I think that as in A this sentence suggests that master cells use themselves for testing and for studying.

E. a transplant, used to test drugs and potentially toxic chemicals, and may study them.

used is not parallel to may study them

gmatter0913 · Answer

IMO B.

'directed' and 'studied' are parallel.

What is the answer?

gmatter0913 · Answer

Option B 
Doctors hope stem cells can be
directed for transplant, using them (transplants?) to test drugs/chemicals,  <--- them refers to stem cells. Possibly, stem cells can be used to test drugs.   I still feel this sentence is correct. 
and
studied to gain insight

KyleWiddison · Answer

Option B can work as a sentence - there isn't a grammatical issue with it. You simply have a parallel list of two items (directed + studied) with a modifier in the middle (using to test...). I would argue that it doesn't make sense to use transplantable organs for drug testing when there is a shortage of transplantable organs. It make much more sense to use stem cells alone for drug testing. I will acknowledge that there is valid debate on this point.

So, let's look at another way to make a decision between B and C. Option B presents us with two parallel items + modifier and Option C presents us with three parallel items. Let's go back to the original to see if we can determine the original intent  . The original sentence is attempting to create a three item list, but fails to keep it parallel. With that is mind, let's fix the parallelism errors and maintain the three item list - that leads us to Option C.

KW

adymehta29 · Answer

i am having trouble in eliminating option D could you please help me out ! Thanks

KyleWiddison · Answer

We can eliminate choice D due to a lack of parallel structure. We are looking for directed, used, and studied. Choice D gives us directed, use, and for studying.

Does that clear this up for you?

KW

WoundedTiger · Answer

Hello Kyle,

C is the answer to this one...
My query is on the usage of them in other options and what "them" refers to...In my opinion...them can refer tissues,organs or cells as well..The sentence will make sense if replace them with any of the options
Eg...

master cells can be directed to grow in organs or tissues, using tissues/organs to test drugs and potentially chemicals,and may study tissues/organs to gain insight...(Use of master cells will not work here)

In your explanation above, them seems to be refer to transplant (singular,I think...but them is plural)...please confirm what them refers to then...

In option C however, 
master cells can be  directed  to grow in Organs or Tissues,
Masters cells can be  used  to test drugs 
and Master cells can be studied..

Clearly it is the master cells which can be used for the purposes...

In option D and E can we say that a transplant ---- a particular type of transplant is being talked about and not transplant in general..can we rule these option on these basis as well...(i know parallelism is best here but looking at what other ways can the answer choice be rejected)

KyleWiddison · Answer

Sorry for the confusion about the pronoun reference (your bolded question above). I did use the word transplants in my explanation, but later I used the more accurate term 'transplantable organs' because them does indeed refer to the organs/tissues (which are used for transplants).

I don't understand your question about options D & E. Can you clarify?

KW

sairam595 · Answer

Can someone explain why option A is incorrect.

master cell can be directed to grow... to use and to study - why this structure is Incorrect!

gmatser1 · Answer

The verb must be past tense to be parallel with "directed" in the not underlined portion of the sentence.

So "use" must be "used"

"study" must be "studied"

Hence A is wrong.

KyleWiddison · Answer

smartguy595,

gmatser1 is correct in pointing out the verb tense issues that make option A non-parallel. I do want to point out that choice A has a significant meaning issues that you should be sure to understand. The structure is setup where the parallel verbs should be passive so that the stem cells receive the action. However, the 2nd and 3rd items in the list (use and may study) are in the active voice and imply that somehow the stem cells are illogically doing drug testing and performing studies. You have to make sure that the correct answer doesn't have that shift from passive to active...

KW

dcummins · Answer

A, D, E are incorrect - break parallelism
 (A) transplant,  use them  to test drugs and potentially toxic chemicals, and  may study them 
(E) a transplant, used to test drugs and potentially toxic chemicals, and  may study them 
(D) a transplant,  use  them for testing drugs and potentially toxic chemicals, and  for studying

B suggests that the organs and tissues could be used to test drugs and chemicals instead of the stem cells.
 (B) transplant,  using them to test drugs and potentially toxic chemicals , and studied

lakshya14 · Answer

If doctors think something in the future will happen then why are we using past tense in the correct answer to make it parallel?

AndrewN · Answer

Hello,  lakshya14 . I understand your confusion, but you are overlooking the modal auxiliary  can be , a construct that is used to project into the future—e.g.,  I hope our wrecked car  can be  salvaged.  The correct sentence uses ellipsis to allow this  can be  to carry over into the other parallel entities:  can be  directed ...    used ... and    studied  .

You might find  this writeup  on auxiliaries and modals to be of interest, although I would not recommend committing everything to memory. (You can get in over your head quickly if you dive into rules upon rules within grammar.)

I hope that helps. Good luck with your studies.

- Andrew

Doctors hope that one day the body’s master cells, called stem cells,

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Sentence Correction (SC - EA only) Questions

Doctors hope that one day the body’s master cells, called stem cells,

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards