Reading Comprehension

Heres the excerpt on which my doubt is based

"Daytime closure of stomata exemplifies a further genetic adaption: guard cells work to minimize day time water loss ,later allowing the stomata to open when conditions are more favourable to gas exchange within the environment"

Q) The author suggests that the guard cells of desert plants act to do which of the following ?

1) facilitate gas and water exchange between the plants and their surroundings
2)cause the stomata of desert plants to remain closed during daytime hours
3) respond to sudden, heavy rainfalls by forcing the stomata to open

A) 1 only
B) 2 only
C) 3 only
D) 1 and 2 only
E) 1,2 and 3


i have a doubt in OA, will post that after seeing some solutions !

is it B?

user123321

Let me know if someone needs the whole passage to be typed. But really this is the only related detail in the passage!

IMO B
I agree with user123321.

Based on the statement, B is the only one that must be true.

1) facilitate gas and water exchange between the plants and their surroundings (only gas exchange has been mentioned)
3) respond to sudden, heavy rainfalls by forcing the stomata to open (minimizing water losses has been mentioned, but nothing about water absorbing or maximizing )

Got a PM on this one:

The answers above seem correct - unless there was another portion of the passage that we need to look to.

Smackmartine is exactly right given the small portion of the passage that we have #2 looks like the only one we can point to...

What is the given answer?

Even i thought B but the OA is D.

Heres the explanation given .

Explanation : This is another detail question , this time focussing on the functionong of guard cells ,mentioned in the sentence that concludes paragraph 1. This sentence discusses two closely related plant features: The stomata and the guard cells. You read first that daytime closure of stomata is an adaption that helps to minimize daytime water loss. The second half clearly implies that its the guard cells that control this opening and closing of stomata. so, the guard cells force the stomata to close during the day,to minimize water loss ,and they later cause the stomata to open ,when conditions for gas exchange between plant and its environment are more favourable. the first two options are thus clearly suggestted.

In my opinion the issue is the usage of word "facilitates",i think it means "making easier" but the usage and explanation here suggest it to mean "to regulate" .

I disagree with the explanation and I agree with you.

The portion you have quoted does not - in my opinion - imply that the cells open to exchange water - only gas. Facilitating water exchange is what is prevented.

If there is no more of the passage to focus on for this question then I would not worry too much about this since it seems to be in doubt...hopefully the rest of the passage was more beneficial to your studies.

David@VeritasPrep wrote:I disagree with the explanation and I agree with you.

The portion you have quoted does not - in my opinion - imply that the cells open to exchange water - only gas. Facilitating water exchange is what is prevented.

If there is no more of the passage to focus on for this question then I would not worry too much about this since it seems to be in doubt...hopefully the rest of the passage was more beneficial to your studies.

I would tend to disagree with you both. D should be the right answer. Here is my explanation.

1. Says: Facilitate gas and water exchange between the plants and surrounding. Passage explicitly states. "Guard cells..... allowing the stomata to open when conditions are more favorable to gas exchange with the environment". Allowing them should be taken as facilitation. The antecedent ... Guard Cells...... for "ALLOWING THEM" is clear and precise. Also the antecedent for THEM is also clear and precise .. STOMATA...

Now the tricky one. They also "PREVENT" water loss to the "ENVIRONMENT" during day time hours. So they are effectively stopping the water exchange and facilitating when water needs to be conserved. Hope this makes sense.

2. Self explanatory.

So it is D... 1 & 2 only.

chufus -

That makes perfect sense! Only not for the GMAT.

On the GMAT we must hold things to a higher standard and cannot really fill in the gaps for people.

Your explanation is brilliant for this question - but this is not an official GMAT question and an official question would never give us D as the correct answer because we are not supposed to fill in the gaps left by the author. (also the use of "facilitate" here means to make easier not to regulate).

Last spring I wrote a well-received article on this subject called "Don't be a Charity Case on the GMAT!" about reading critically and not generously.

https://www.beatthegmat.com/mba/2011/03/ ... n-the-gmat

I agree with what david said !