Unlike transplants between identical twins, whose genetic endowment is

Besides changes the intended meaning of the sentence.

"Besides" is used when you must take two or more considerations together.

Besides doing regular exercise, you must also maintain balanced diet to keep healthy.
Means; "Doing regular exercise" should co-exist with the other condition i.e. "eating healthy diet". In other words, besides is kind of supportive word.

What we need is a contrast:

What the sentence is trying to convey:
If the transplants involve identical twins, antirejection drugs are NOT necessary. But, if the transplants involve other patients who are NOT identical twins, antirejection drugs are necessary. There is a contrast.

Besides transplants involving identical twins with the same genetic endowment, all patients receiving hearts or other organs must take antirejection drugs for the rest of their lives.

This statement appears as if "transplants involving identical twins with the same genetic endowment" is some sort of ACT or condition that all patients have to fulfill prior to getting the antirejection drugs.

1. Let’s appreciate that it is ' patients' that have to be compared with another set of patients or people
2. In this case A , B, D and E compare either transplants or transplant and therefore are wrong comparisons. C only compares in essence identical twins (meaning identical wins who receive transplants) with ‘all patients’. Hence, the right answer.
3. Lucky that four out of the five choices can be stroked down on the very first count .

The basic take - away from this topic is that, whenever a modifier starts a sentence, it is an adjectival modifier, that has to compulsorily modify the noun that lies just after. The adjectival modifier is always a phrase rather than a clause. In the given case, choices A, B, D, and E use adjectival phrases to introduce their sentences (note the absence of any verb in any of these four introducers). On the contrary, the choice C is a complex sentence with a subordinate clause followed by the main clause. In a complex sentence, there is no modification relation between the two clauses, since both are clauses with their own verbs. That is the reason that C stands out from the rest.

Request you not to write your queries/answers/opinions in question window. It prevents ppl from analysing the question. The whole purpose of GMAT Club forum goes wasted by doing so.


You have response windows to do all such things.

Unlike transplants between identical twins, whose genetic endowment is the same, all patients receiving hearts of other organs must take antirejection drugs for the rest of their lives.

A. Unlike transplants between identical twins, whose genetic endowment is the same
B. Besides transplants involving identical twins with the same genetic endowment
C. Unless the transplant involves identical twins who have the same genetic endowment
D. Aside from a transplant between identical twins with the same genetic endowment
E. Other than transplants between identical twins, whose genetic endowment is the same

IMO, it is too much hair-splitting to worry whether the relative pronoun ‘who’ and the adverbial 'with' refer to the identical twins that have the same genome or not. For Our SC purpose, we can take so that the relative pronoun ‘who’ does refer to all identical twins. The gist of the topic is that when an organ transplant is undergone, the identical twins are better placed than other mortals are.

Because the latest research (as latest as 2008) shows that, the so-called identical twins can differ in their genetic make-up. Pl. link to the reference below.
https://www.scientificamerican.com/artic ... identical/

Since scientific community itself is caught at cross-roads, we can ignore it I believe. There are solid other reasons of faulty comparison to dispense with A, B , D and E.

The official explanation for rejecting B and D seems rather differing.

Hi Experts,

egmat, mikemcgarry, sayantanc2k

I want to thoroughly understand the difference between the usage of with and who here:

(B) Besides transplants involving identical twins with the same genetic endowment
(C) Unless the transplant involves identical twins who have the same genetic endowment

Please help

Elaborating on my confusion and some analysis i did:

Here is the official explanation:
You answered "Unless the transplant involves identical twins who have the same genetic endowment" and that's correct because:
In A and B, the phrases beginning Unlike… and Besides… modify patients, the subject of the main clause; thus A absurdly states that Unlike transplants…, patients…must take…drugs, and B that all patients except for transplants…must take… drugs. In B and D the expression identical twins with the same genetic endowment wrongly suggests that only some identical twin pairs are genetically identical. In E, the construction Other than transplants…, all patients… must take… drugs illogically suggests, as in B, that some patients are transplants. Choice C, the best answer, solves these problems by using a clause introduces by Unless to describe the exception to the rule and a nonrestrictive clause beginning with who to describe the characteristic attributed to all identical twins.

Confusion and Analysis:
As it looks like both of the following have the same meaning, I got confused by the explanation (highlighted), especially for choice correct choice C in which who is termed as nonrestrictive).
(B) Besides transplants involving identical twins with the same genetic endowment
(C) Unless the transplant involves identical twins who have the same genetic endowment

I found one of RON's posts in which he mentions that for "a nonrestrictive clause beginning with who to describe the characteristic attributed to all identical twins." to be true there has to be a comma before "who" in choice . here is the link: https://www.manhattanprep.com/gmat/forums/restrictive-vs-non-restrictive-t25787.html#p96242
Yes that's the concept we have learned about norestrictive or nonessential modifiers.

BUT when i looked up meaning of "who" that says - "used to introduce a clause giving further information about a person or people previously mentioned."
Now this seems to confirm that no comma is required and given official explanation is correct.

I need Experts' opinion on my understanding.

Thanks

Hi Experts,

Could you please guide how to eliminate Option-B AND D?
As per RON, B and D can also be eliminated because they compare transplants with people. Could you please shed some light on this ?

Regards
Rohit

aarkay87

Hi Rohit,

The Number One Rule of Comparisons is that only like and comparable things can be compared in prose. This means that the things being compared should belong to the same class, else we run the risk of an "Illogical Comparison".

Answer choice B:

Besides transplants involving identical twins with the same genetic endowment, all patients receiving hearts or other organs must take antirejection drugs for the rest of their lives.

- The preposition 'besides' indicates a comparison between its object 'transplants' and the subject of the sentence 'all patients'.
- That means 'apart from transplants involving identical twins, all patients receiving hearts or other organs must take antirejection drugs for the rest of their lives'
- To further elucidate, the above sentence illogically implies that both 'transplants involving identical twins' and 'all patients receiving hearts or other organs' must take antirejection drugs for the rest of their lives.
- Hence, this answer choice is highly illogical.

Answer choice D:

Aside from a transplant between identical twins with the same genetic endowment, all patients receiving hearts or other organs must take antirejection drugs for the rest of their lives.
[/i]
- This answer choice is identical to choice B, in that it makes the same illogical comparison as choice B does.
- Aside from is the North American equivalent of the phrasal preposition Apart from.
- That means 'aside/apart from a transplant between identical twins, all patients receiving hearts or other organs must take antirejection drugs for the rest of their lives'.
- Hence, answer choice D is equally illogical.

Hope this helps.

Best,

GMAT Whiz Team

HKD1710

Hi,

This is in response to your query on the restrictive/non-restrictive issue:

Here's what you need to bear in mind while preparing for the actual GMAT Exam.

In this question:
- In its current form, the relative clause 'who have the same genetic endowment' in answer choice C is restrictive.
- For it to be non-restrictive, there would have been a comma before 'who'.
- Honestly, when I first solved this question, I interpreted choice C as 'not all identical twins have the same genetic endowment'. (Keeping general knowledge aside, of course)
- I was able to arrive at the correct answer by eliminating all choices with an illogical comparison in them.
- It was when I read your query that I did some digging. Identical Twins do have the exact same genetic endowment or DNA at birth. Scientists have said that, later on in life, even identical twins develop epigenetic changes in their DNA. However, since we're talking about 'endowment', that part is pretty much air tight.
- Then, the official explanation you shared also mentioned the same thing.

Conclusion: This answer choice C has a typographical error in it. There should be a comma before 'who'. There are no two ways about this.

Recommendation: Try to locate the original version of both this question and its official explanation. Typos are replete in questions and explanations posted on forums. I'm confident the original version will have a comma in it, considering choices A and D already do.

Hope this helps.

Best,

GMAT Whiz Team

HI team,

Can we then conclude that " Besides, Apart & Aside are comparison triggers?"

Thanks

GMATWhizTeam
what is correct phrase - "transplant between identical twins" or " transplant involves identical twins".

I understand that this phrase - "transplant between identical twins" is wrong. the phrase can also mean - exchange of organs.

please correct my understanding.

Hello sourabhgx,

We hope this finds you well.

To answer your query, neither phrase is entirely incorrect, but "transplant involving identical twins" is clearer and thus superior.

We hope this helps.
All the best!
Experts' Global Team

My process of elimination was- 
a. In A and E, I found 2 issues - One is the apparent faulty comparison- 'Transplants vs patients'. However, my question is - I believe that the verb 'is' is used for the subject 'twins' genetic endowment' and not 'genetic endowment' alone, which is why I think these 2 options use the wrong SVA and it should 'are' and not 'is'. I am not sure if I am able to apply the SVA correctly but I did think along these lines as well.

b. D states 'a transplant' which makes it look as though it's just that one transplant that we are talking about, however, that is not true. I eliminated this option basis the reason I mentioned above. 

c.B not only repeated the faulty comparison trap but also altered the meaning. It seemed as though the sentence was not saying 'only in the case of twins something is required or done differently' - meaning unless there is a necessity we do xx but was now saying 'apart from twins xx in other patients is required' - except for twins we do xx.I am not too sure if the meaning difference that I am talking about makes any sense here but please could you see if there is anything wrong with it?

Please can any of the experts GMATNinja Bunuel help me this?

Can I conclude that if phrase is used in the beginning of the sentence and there is comma, after comma ALWAYS the word (noun) modifying the phrase should be there and in case clause is used (identified by the usage of noun and verb) can say that after comma there is no compulsion of using noun / subject.

Not always. For example, following is a correct official sentence:

Unlike the virginal, which has a single set of strings that run parallel to the front edge of the instrument, the harpsichord has several sets of strings placed at right angles to its front edge.

Notice that the introductory phrase "Unlike the virginal" has a comma after it, but this phrase is followed by a relative clause ("which has...") modifying "virginal".

So, the learning would be that there should be an apples to apples comparison.

KarishmaB EMPOWERgmatVerbal

1. Can we eliminate options based on the use of "Unlike / Besides / Unless / Aside / Other
2. As per gmatclub - "In B and D the expression identical twins with the same genetic endowment wrongly suggests that only some identical twin pairs are genetically identical."
Won't the same logic apply while using pronoun "who"