Check GMAT Club Decision Tracker for the Latest School Decision Releases https://gmatclub.com/AppTrack

 It is currently 25 May 2017, 05:37

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# Networks of blood vessels in bats’ wings serve only to dispe

Author Message
TAGS:

### Hide Tags

Intern
Joined: 13 Apr 2011
Posts: 15
Followers: 1

Kudos [?]: 29 [1] , given: 7

Networks of blood vessels in bats’ wings serve only to dispe [#permalink]

### Show Tags

08 Apr 2014, 18:00
1
KUDOS
28
This post was
BOOKMARKED
00:00

Difficulty:

95% (hard)

Question Stats:

40% (02:20) correct 60% (01:32) wrong based on 723 sessions

### HideShow timer Statistics

Networks of blood vessels in bats’ wings serve only to disperse heat generated in flight. This heat is generated only because bats flap their wings. Thus paleontologists’ recent discovery that the winged dinosaur Sandactylus had similar networks of blood vessels in the skin of its wings provides evidence for the hypothesis that Sandactylus flew by flapping its wings, not just by gliding.

The argument in the passage relies on which of the following assumptions?

(A) Sandactylus would not have had networks of blood vessels in the skin of its wings if these networks were of no use to Sandactytus.

(B) All creatures that fly by flapping their wings have networks of blood vessels in the skin of their wings.

(C) winged dinosaurs that flapped their wingsin flight would have been able to fly more effectively than winged dinosaurs that could only glide.

(D) If Sandactylus flew by flapping its wings, then paleontologists would certainly be able to findsome evidence that it did so.

(E) Heat generated by Sandactylus in flapping its wings in flight could not have been dispersed by anything other than the blood vessels in its wings.
[Reveal] Spoiler: OA

Last edited by carcass on 09 Apr 2014, 03:53, edited 1 time in total.
Edited the title of the question and formatted properly
If you have any questions
New!
Manager
Joined: 24 Oct 2013
Posts: 175
Schools: LBS '18
GMAT 1: 720 Q49 V38
WE: Design (Transportation)
Followers: 9

Kudos [?]: 39 [0], given: 83

### Show Tags

08 Apr 2014, 20:25
Let us say these networks were of use to the dinosaur in such a way that these networks helped the dinosaur to to have flexible wings. Now that goes well with option A that says - 'andactylus would not have had networks of blood vessels in the skin of its wings if these networks were of no use to Sandactytus.'

But that doesn't necessarily prove the hypothesis that Sandactylus flew by flapping its wings, not just by gliding.

IMO E
Manager
Joined: 20 Dec 2013
Posts: 132
Followers: 11

Kudos [?]: 98 [0], given: 1

### Show Tags

08 Apr 2014, 22:36
The argument makes an analogy between bats' wings and those of Sandactylus. The basic assumption is that if the Sandactylus had networks of blood vessels,it was solely due to flapping of wings. The correct option will be A.

You can also apply the negation test to the option and check.
_________________

76000 Subscribers, 7 million minutes of learning delivered and 5.6 million video views

Perfect Scores
http://perfectscores.org

Senior Manager
Joined: 17 Sep 2013
Posts: 388
Concentration: Strategy, General Management
GMAT 1: 730 Q51 V38
WE: Analyst (Consulting)
Followers: 19

Kudos [?]: 295 [0], given: 139

### Show Tags

08 Apr 2014, 23:29
Between A & E

E- Supports that the Srus used to flap its wings any ways but had no mechanism to diesperse the heat but the blood vessels
A- Supports the conclusion that the Dino has blood vessels-->Hence it flapped its wings..As blood vessels did not serve any other purpose & neither were they redundant
_________________

Appreciate the efforts...KUDOS for all
Don't let an extra chromosome get you down..

Manager
Joined: 04 Jan 2014
Posts: 124
Followers: 1

Kudos [?]: 12 [0], given: 24

Re: Networks of blood vessels in bats’ wings serve only to dispe [#permalink]

### Show Tags

27 Apr 2014, 00:01
Is A indeed the correct answer?
Senior Manager
Joined: 12 Mar 2010
Posts: 361
Concentration: Marketing, Entrepreneurship
GMAT 1: 680 Q49 V34
Followers: 2

Kudos [?]: 193 [0], given: 87

Re: Networks of blood vessels in bats’ wings serve only to dispe [#permalink]

### Show Tags

27 Apr 2014, 05:01
Looks like E to me. Is A the answer?

Senior Manager
Joined: 08 Apr 2012
Posts: 455
Followers: 2

Kudos [?]: 61 [0], given: 58

Re: Networks of blood vessels in bats’ wings serve only to dispe [#permalink]

### Show Tags

25 Jun 2014, 10:28
chshashankreddy wrote:
Networks of blood vessels in bats’ wings serve only to disperse heat generated in flight. This heat is generated only because bats flap their wings. Thus paleontologists’ recent discovery that the winged dinosaur Sandactylus had similar networks of blood vessels in the skin of its wings provides evidence for the hypothesis that Sandactylus flew by flapping its wings, not just by gliding.

The argument in the passage relies on which of the following assumptions?

(A) Sandactylus would not have had networks of blood vessels in the skin of its wings if these networks were of no use to Sandactytus.

(B) All creatures that fly by flapping their wings have networks of blood vessels in the skin of their wings.

(C) winged dinosaurs that flapped their wingsin flight would have been able to fly more effectively than winged dinosaurs that could only glide.

(D) If Sandactylus flew by flapping its wings, then paleontologists would certainly be able to findsome evidence that it did so.

(E) Heat generated by Sandactylus in flapping its wings in flight could not have been dispersed by anything other than the blood vessels in its wings.

I also went for E on this one.
Experts?
Intern
Joined: 08 Nov 2012
Posts: 8
Followers: 0

Kudos [?]: 4 [1] , given: 1

Re: Networks of blood vessels in bats’ wings serve only to dispe [#permalink]

### Show Tags

03 Jul 2014, 16:26
1
KUDOS
I really believe only possible choice is B. I think this is a horrible question though.

A - Network of blood vessels used for different reasons (say to breath). So A is true, but does not support the stem.
C - Clearly wrong
D - Clearly wrong
E - Ok let's say that it's true, heat generated by Sandactylus in flapping its wings in flight could not have been dispersed by anything other than the blood vessels in its wings. And then? Does it tell us that Sandactylus flapped its wings? Definitely not.

B - Since all creatures that flap have blood vessel network hence Sandactylus (that has this network from the stem) must flap its wings (given that this caractheristic has remained the same over time and across animals).
Director
Joined: 23 Jan 2013
Posts: 586
Schools: Cambridge'16
Followers: 1

Kudos [?]: 25 [0], given: 41

Re: Networks of blood vessels in bats’ wings serve only to dispe [#permalink]

### Show Tags

05 Jul 2014, 03:46
Between A and E but negation clearly affect A. Answer is A
Senior Manager
Joined: 17 Sep 2013
Posts: 388
Concentration: Strategy, General Management
GMAT 1: 730 Q51 V38
WE: Analyst (Consulting)
Followers: 19

Kudos [?]: 295 [0], given: 139

Re: Networks of blood vessels in bats’ wings serve only to dispe [#permalink]

### Show Tags

05 Jul 2014, 04:31
chshashankreddy wrote:
Networks of blood vessels in bats’ wings serve only to disperse heat generated in flight. This heat is generated only because bats flap their wings. Thus paleontologists’ recent discovery that the winged dinosaur Sandactylus had similar networks of blood vessels in the skin of its wings provides evidence for the hypothesis that Sandactylus flew by flapping its wings, not just by gliding.

The argument in the passage relies on which of the following assumptions?

(A) Sandactylus would not have had networks of blood vessels in the skin of its wings if these networks were of no use to Sandactytus.
Negate: S could have had useless networks of blood vessels in the skin of its wings..The whole thing that vessels are here necessarily to fulfill a purpose...A it is
(E) Heat generated by Sandactylus in flapping its wings in flight could not have been dispersed by anything other than the blood vessels in its wings.

Negate: S had other ways to disperse heat generated by flapping..So what..It still had the blood vessels as one of the way to disperse the heat..Argument intact..E fails
_________________

Appreciate the efforts...KUDOS for all
Don't let an extra chromosome get you down..

Manager
Joined: 27 Jul 2012
Posts: 127
Followers: 0

Kudos [?]: 85 [6] , given: 101

Re: Networks of blood vessels in bats’ wings serve only to dispe [#permalink]

### Show Tags

05 Jul 2014, 04:58
6
KUDOS
1
This post was
BOOKMARKED
The argument in the passage relies on which of the following assumptions?

(A) Sandactylus would not have had networks of blood vessels in the skin of its wings if these networks were of no use to Sandactytus.
the network of blood vessels serve only to disperse heat generated in flight.
so it has a certain function and usage.
negation of this option will break the argument apart

(B) All creatures that fly by flapping their wings have networks of blood vessels in the skin of their wings. we can infer from the argument that those creatures that their wings have networks of blood vessels in the skin of their wings fly by flapping their wings not vice versa.

(C) winged dinosaurs that flapped their wings in flight would have been able to fly more effectively than winged dinosaurs that could only glide.

(D) If Sandactylus flew by flapping its wings, then paleontologists would certainly be able to find some evidence that it did so. they've already found some evidence.. network of blood vessels.

(E) Heat generated by Sandactylus in flapping its wings in flight could not have been dispersed by anything other than the blood vessels in its wings.

we have a premise:Networks of blood vessels in bats’ wings serve only to disperse heat generated in flight. ---> there might be other ways that bats disperse heat generated in flight. however, the usage of Networks of blood vessels in bats' wings is only to disperse heat generated in flight------- so, E is incorrect
Manager
Joined: 17 Jul 2013
Posts: 104
Followers: 0

Kudos [?]: 6 [0], given: 67

Re: Networks of blood vessels in bats’ wings serve only to dispe [#permalink]

### Show Tags

07 Jul 2014, 02:30
bb61 wrote:
The argument in the passage relies on which of the following assumptions?

(A) Sandactylus would not have had networks of blood vessels in the skin of its wings if these networks were of no use to Sandactytus.
the network of blood vessels serve only to disperse heat generated in flight.
so it has a certain function and usage.
negation of this option will break the argument apart

(B) All creatures that fly by flapping their wings have networks of blood vessels in the skin of their wings. we can infer from the argument that those creatures that their wings have networks of blood vessels in the skin of their wings fly by flapping their wings not vice versa.

(C) winged dinosaurs that flapped their wings in flight would have been able to fly more effectively than winged dinosaurs that could only glide.

(D) If Sandactylus flew by flapping its wings, then paleontologists would certainly be able to find some evidence that it did so. they've already found some evidence.. network of blood vessels.

(E) Heat generated by Sandactylus in flapping its wings in flight could not have been dispersed by anything other than the blood vessels in its wings.

we have a premise:Networks of blood vessels in bats’ wings serve only to disperse heat generated in flight. ---> there might be other ways that bats disperse heat generated in flight. however, the usage of Networks of blood vessels in bats' wings is only to disperse heat generated in flight------- so, E is incorrect

But I can see the correct option as E of the same question in another link .. Can you please explain the mismatch ..
GMAT Club Legend
Joined: 01 Oct 2013
Posts: 10367
Followers: 998

Kudos [?]: 225 [0], given: 0

Re: Networks of blood vessels in bats’ wings serve only to dispe [#permalink]

### Show Tags

18 Sep 2015, 12:14
Hello from the GMAT Club VerbalBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
Intern
Joined: 16 Oct 2015
Posts: 21
Followers: 0

Kudos [?]: 0 [0], given: 6

Re: Networks of blood vessels in bats’ wings serve only to dispe [#permalink]

### Show Tags

02 Nov 2015, 09:51
B is too extreme for me (All creatures...). Regarding E, is more a conclusion than an assumption. Besides, by stating that "Heat generated by Sandactylus in flapping its wings in flight could not have been dispersed by anything other than the blood vessels in its wings" is like an overstatement since the passage does not say so about bats; "networks of blood vessels in bats' wings are used for heat dispersion and that's their only use in the case of bats but it cannot be assumed that is the only mechanism for heat dispersion, even in the case of bats. So I had to go with A in this case.
Intern
Joined: 20 Aug 2013
Posts: 8
Concentration: Entrepreneurship, Operations
GRE 1: 330 Q168 V162
Followers: 0

Kudos [?]: 4 [1] , given: 0

Re: Networks of blood vessels in bats’ wings serve only to dispe [#permalink]

### Show Tags

23 May 2016, 10:35
1
KUDOS
'The heat generated by Sandactylus' as presented in option E is stated as a known fact and used to construct an assumption. This can't be the correct assumption because the first and more fundamental assumption inherent in the hypothesis revolves around the Sandactylus generating heat in the first place.
VP
Joined: 09 Jun 2010
Posts: 1392
Followers: 5

Kudos [?]: 130 [0], given: 856

Re: Networks of blood vessels in bats’ wings serve only to dispe [#permalink]

### Show Tags

24 May 2016, 05:11
chshashankreddy wrote:
Networks of blood vessels in bats’ wings serve only to disperse heat generated in flight. This heat is generated only because bats flap their wings. Thus paleontologists’ recent discovery that the winged dinosaur Sandactylus had similar networks of blood vessels in the skin of its wings provides evidence for the hypothesis that Sandactylus flew by flapping its wings, not just by gliding.

The argument in the passage relies on which of the following assumptions?

(A) Sandactylus would not have had networks of blood vessels in the skin of its wings if these networks were of no use to Sandactytus.

(B) All creatures that fly by flapping their wings have networks of blood vessels in the skin of their wings.

(C) winged dinosaurs that flapped their wingsin flight would have been able to fly more effectively than winged dinosaurs that could only glide.

(D) If Sandactylus flew by flapping its wings, then paleontologists would certainly be able to findsome evidence that it did so.

(E) Heat generated by Sandactylus in flapping its wings in flight could not have been dispersed by anything other than the blood vessels in its wings.

this is hard because we see 2 close answers a and e. I search on internet to find better explanation of why e is wrong . i find no other explanations.

this is official and so, we should study it carefully. certainly,we will meet this case on test day

the takeaway is

when facing 2 close answer, we should use negation test. this is the way gmat test us negation

assumption is most basic and hard question.
_________________

visit my facebook to help me.
on facebook, my name is: thang thang thang

Re: Networks of blood vessels in bats’ wings serve only to dispe   [#permalink] 24 May 2016, 05:11
Similar topics Replies Last post
Similar
Topics:
6 #Top150 CR: Networks of blood vessels in bats' wings 4 27 Apr 2016, 03:51
2 Networks of blood vessels in 1 14 Sep 2015, 21:53
4 The bones in a bat's wing that are near the tip have less 7 26 Aug 2014, 00:58
5 Networks of blood vessels in bats wings serve only 7 06 Oct 2015, 13:51
3 The human body s blood vessels and veins are designed to 5 10 Oct 2016, 04:10
Display posts from previous: Sort by