Find all School-related info fast with the new School-Specific MBA Forum

It is currently 16 Sep 2014, 13:37

Close

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

The chemical adenosine is released by brain cells when those

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Manager
Manager
avatar
Joined: 06 May 2009
Posts: 78
Followers: 2

Kudos [?]: 10 [0], given: 3

The chemical adenosine is released by brain cells when those [#permalink] New post 28 Jul 2009, 02:54
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

71% (03:29) correct 29% (02:23) wrong based on 9 sessions
The chemical adenosine is released by brain cells when those cells are active.
Adenosine then binds to more and more sites on cells in certain areas of the
brain, as the total amount released gradually increases during wakefulness.
During sleep, the number of sites to which adenosine is bound decreases. Some
researchers have hypothesized that it is the cumulative binding of adenosine to a
large number of sites that causes the onset of sleep.
Which of the following, if true, provides the most support for the researchers’
hypothesis?
A. Even after long periods of sleep when adenosine is at its lowest concentration
in the brain, the number of brain cells bound with adenosine remains
very large.
B. Caffeine, which has the effect of making people remain wakeful, is known to interfere with the binding of adenosine to sites on brain cells.
C. Besides binding to sites in the brain, adenosine is known to be involved in
biochemical reactions throughout the body.
D. Some areas of the brain that are relatively inactive nonetheless release
some adenosine.
E. Stress resulting from a dangerous situation can preserve wakefulness even
when brain levels of bound adenosine are high.
Director
Director
User avatar
Joined: 03 Jun 2009
Posts: 805
Location: New Delhi
WE 1: 5.5 yrs in IT
Followers: 63

Kudos [?]: 395 [0], given: 56

GMAT Tests User
Re: chemical adenosine [#permalink] New post 28 Jul 2009, 03:26
IMO B

A. Even after long periods of sleep when adenosine is at its lowest concentration in the brain, the number of brain cells bound with adenosine remains very large. -Though the number of bindings are very large, but still the option is saying that it is at its lowest concentration. That clearly means that at higher concentration the number of bindings will be even much larger. This option doesn't support "Some researchers have hypothesized that it is the cumulative binding of adenosine to a large number of sites that causes the onset of sleep."
B. Caffeine, which has the effect of making people remain wakeful, is known to interfere with the binding of adenosine to sites on brain cells. -Correct. The researchers are saying that increase in binding makes people sleepy. This option is giving an example when a decrease in binding keeps people awake. Hence supporting the researchers work.
C. Besides binding to sites in the brain, adenosine is known to be involved in biochemical reactions throughout the body. -Irrelevant.
D. Some areas of the brain that are relatively inactive nonetheless release some adenosine. -Irrelevant. Referring to very small amount of adenosine. "Some areas...release some..."
E. Stress resulting from a dangerous situation can preserve wakefulness even
when brain levels of bound adenosine are high. -Irrelevant. Its talking about a one off case.
_________________

ISB 2011-12 thread | Ask ISB Alumni @ ThinkISB
All information related to Indian candidates and B-schools | Indian B-schools accepting GMAT scores
Self evaluation for Why MBA?

Director
Director
avatar
Joined: 05 Jun 2009
Posts: 852
WE 1: 7years (Financial Services - Consultant, BA)
Followers: 8

Kudos [?]: 182 [0], given: 106

GMAT Tests User
Re: chemical adenosine [#permalink] New post 28 Jul 2009, 10:51
Yep B
_________________

Consider kudos for the good post ... :beer
My debrief : journey-670-to-720-q50-v36-long-85083.html

Director
Director
User avatar
Joined: 01 Apr 2008
Posts: 909
Schools: IIM Lucknow (IPMX) - Class of 2014
Followers: 15

Kudos [?]: 214 [0], given: 18

GMAT Tests User
Re: chemical adenosine [#permalink] New post 28 Jul 2009, 12:51
bigoyal wrote:
IMO B
B. Caffeine, which has the effect of making people remain wakeful, is known to interfere with the binding of adenosine to sites on brain cells. -Correct. The researchers are saying that increase in binding makes people sleepy. This option is giving an example when a decrease in binding keeps people awake. Hence supporting the researchers work.

B only says that caffeine 'interferes' with the binding. Can we assume that it decreases the binding for it's so-called effect? For me this option only says that caffeine has some kind of effect on brain cells.

OA pls?
Director
Director
avatar
Joined: 05 Jun 2009
Posts: 852
WE 1: 7years (Financial Services - Consultant, BA)
Followers: 8

Kudos [?]: 182 [0], given: 106

GMAT Tests User
Re: chemical adenosine [#permalink] New post 28 Jul 2009, 13:32
Economist wrote:
bigoyal wrote:
IMO B
B. Caffeine, which has the effect of making people remain wakeful, is known to interfere with the binding of adenosine to sites on brain cells. -Correct. The researchers are saying that increase in binding makes people sleepy. This option is giving an example when a decrease in binding keeps people awake. Hence supporting the researchers work.

B only says that caffeine 'interferes' with the binding. Can we assume that it decreases the binding for it's so-called effect? For me this option only says that caffeine has some kind of effect on brain cells.

OA pls?


I think in this context:
interfere is used as "Come between so as to be hindrance or obstacle"(Wordweb dictionary meaning)
_________________

Consider kudos for the good post ... :beer
My debrief : journey-670-to-720-q50-v36-long-85083.html

Director
Director
User avatar
Joined: 03 Jun 2009
Posts: 805
Location: New Delhi
WE 1: 5.5 yrs in IT
Followers: 63

Kudos [?]: 395 [0], given: 56

GMAT Tests User
Re: chemical adenosine [#permalink] New post 28 Jul 2009, 20:39
Economist wrote:
bigoyal wrote:
IMO B
B. Caffeine, which has the effect of making people remain wakeful, is known to interfere with the binding of adenosine to sites on brain cells. -Correct. The researchers are saying that increase in binding makes people sleepy. This option is giving an example when a decrease in binding keeps people awake. Hence supporting the researchers work.

B only says that caffeine 'interferes' with the binding. Can we assume that it decreases the binding for it's so-called effect? For me this option only says that caffeine has some kind of effect on brain cells.

OA pls?


I think so, as it is mentioned in the option that "Caffeine....is known to interfere with the binding of adenosine to sites on brain cells"
So if its interfering with the binding process, it surely will at least slow down the process of binding process, hence not letting it to increase.
_________________

ISB 2011-12 thread | Ask ISB Alumni @ ThinkISB
All information related to Indian candidates and B-schools | Indian B-schools accepting GMAT scores
Self evaluation for Why MBA?

Manager
Manager
avatar
Joined: 06 May 2009
Posts: 78
Followers: 2

Kudos [?]: 10 [0], given: 3

Re: chemical adenosine [#permalink] New post 28 Jul 2009, 20:43
bigoyal wrote:
Economist wrote:
bigoyal wrote:
IMO B
B. Caffeine, which has the effect of making people remain wakeful, is known to interfere with the binding of adenosine to sites on brain cells. -Correct. The researchers are saying that increase in binding makes people sleepy. This option is giving an example when a decrease in binding keeps people awake. Hence supporting the researchers work.

B only says that caffeine 'interferes' with the binding. Can we assume that it decreases the binding for it's so-called effect? For me this option only says that caffeine has some kind of effect on brain cells.

OA pls?


I think so, as it is mentioned in the option that "Caffeine....is known to interfere with the binding of adenosine to sites on brain cells"


OA is B
Director
Director
User avatar
Joined: 01 Apr 2008
Posts: 909
Schools: IIM Lucknow (IPMX) - Class of 2014
Followers: 15

Kudos [?]: 214 [0], given: 18

GMAT Tests User
Re: chemical adenosine [#permalink] New post 29 Jul 2009, 02:28
Thanks ankur55..good question:) and thanks all for the discussion.
Actually I did some over-engineering..
I was between C and E. ( which are almost similar )

Now that I know the OA...I can understand the subtle difference. C says that X affects the cells ( increase or decrease, but most probably decreases the binding to have its effect ) and thereby causes wakefulness. So we are sure that wakefulness or sleep is affected by the binding.

E says that Y 'preserves' wakefulness inspite of high concentration. It does not say anything about the effect of Y on the cells. So may be something else is causing sleep. This actually weakens the argument.

Nice pattern for cause-effect CRs.
Manager
Manager
avatar
Joined: 21 Jun 2009
Posts: 156
Followers: 3

Kudos [?]: 8 [0], given: 1

Re: chemical adenosine [#permalink] New post 29 Jul 2009, 06:37
Good question.
Intern
Intern
avatar
Joined: 29 Jun 2010
Posts: 1
Followers: 0

Kudos [?]: 0 [0], given: 0

Re: chemical adenosine [#permalink] New post 12 Jul 2010, 03:55
Vast collection of web tools.100% valid. Visit - Trustdownload
Senior Manager
Senior Manager
User avatar
Joined: 03 Dec 2012
Posts: 367
Followers: 0

Kudos [?]: 36 [0], given: 291

Re: The chemical adenosine is released by brain cells when those [#permalink] New post 01 Dec 2013, 18:22
I don't think E is irrelevant. It is the 2nd best option to B. It suggests that high conc of adenosine makes people sleepy but a dangerous situation keeps them awake clearly suggesting that adenosine aids in sleep.
Intern
Intern
avatar
Joined: 27 Jul 2011
Posts: 47
Followers: 1

Kudos [?]: 19 [0], given: 2

Re: The chemical adenosine is released by brain cells when those [#permalink] New post 02 Dec 2013, 01:24
My breakdown reasoning:
Cumulative binding of adenosine ------> sleep
OTHER/ NO (adenosine) -------> NO sleep

Therefore answer B
Re: The chemical adenosine is released by brain cells when those   [#permalink] 02 Dec 2013, 01:24
    Similar topics Author Replies Last post
Similar
Topics:
The chemical adenosine is released by brain cells when those Jp27 3 11 Nov 2012, 04:42
1 Recently documentedc, the production of new brain cells, devinawilliam83 3 05 Nov 2011, 21:29
The chemical adenosine is released by brain cells when those aurobindo 6 31 Jan 2007, 06:28
The chemical adenosine is released by brain cells when those jerrywu 6 18 Sep 2006, 00:32
Alcohol may interface with the ability of the brain cells as mbassmbass04 2 11 Dec 2004, 09:54
Display posts from previous: Sort by

The chemical adenosine is released by brain cells when those

  Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group and phpBB SEO

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.