GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 17 Jul 2018, 01:07

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.

Close

Request Expert Reply

Confirm Cancel

Networks of blood vessels in bats' wings serve only to disperse heat g

  post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Retired Moderator
User avatar
P
Status: The best is yet to come.....
Joined: 10 Mar 2013
Posts: 535
GMAT ToolKit User
Re: Networks of blood vessels in bats' wings serve only to disperse heat g [#permalink]

Show Tags

New post 16 Aug 2017, 21:44
VeritasPrepKarishma wrote:
diegmat 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 Sandactylus.

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 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.

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.


Responding to a pm:

This is not an easy question - especially if you are trying to explain the answer.
So first let's try to understand how the argument is structured. I will use variables to make it easier:

Networks of blood vessels in wings - A
heat generated in flight by flapping wings - B

Given Argument:
Bats have A. Bats have B. A's only job is to get rid of B.
Dinos had A too. Hence, Dinos had B too.

What is the assumption? That A must have had a purpose in Dinos too (getting rid of B). You cannot have A without having a job for it. Just because Dinos had A, we are concluding that they must have had B too. We are assuming that A must have had a purpose. This is option (A) and is the answer.

Are we assuming that we cannot get rid of B without A? No. (This is what option (E) says)
When would this be the assumption?
If the argument were a little different: Dinos had B. Hence, Dinos had A too.
In this argument, the assumption would have been that we cannot get rid of B without A.
But given the original argument, this is not the assumption. Hence, answer is not (E).


In case of A, I am not clear how can we assume that the function of networks of blood vessels in Bat's wings is SAME as the function of networks of blood vessels in Dino's wings! It may happen that networks of blood vessels in Bat's wings are used for only to disperse heat generated in flight, whereas networks of blood vessels in Bat's wings are used for only to circulate blood or anything else.

Would you please help me to get out of it?
_________________

Hasan Mahmud

e-GMAT Discount CodesVeritas Prep GMAT Discount CodesKaplan GMAT Prep Discount Codes
1 KUDOS received
Manager
Manager
avatar
S
Joined: 17 Aug 2012
Posts: 156
Location: India
Concentration: General Management, Strategy
Schools: Copenhagen, ESMT"19
GPA: 3.75
WE: Consulting (Energy and Utilities)
GMAT ToolKit User
Re: Networks of blood vessels in bats' wings serve only to disperse heat g [#permalink]

Show Tags

New post 29 Aug 2017, 10:49
1
If we negate (E) - Heat generated by Sandactylus in flaping its wings in flight could have been dispersed by things other than the blood vessels in its wings. It does not invalidate our conclusion. However, if we negate (A), it reads Sandactylus would have had networks of blood vessels in the skin of its wings if these networks were of no
use of to Sandactylus . If the vessels were "of no use" to Sandactylus, this directly undermines the evidence on which the entire conclusion is based which is Network of blood vessels in bats' wings serve only to disperse heat generated in flight.
BSchool Forum Moderator
User avatar
D
Joined: 28 Mar 2017
Posts: 1040
Location: India
Concentration: Finance, Technology
GMAT 1: 730 Q49 V41
GPA: 4
CAT Tests
Re: Networks of blood vessels in bats' wings serve only to disperse heat g [#permalink]

Show Tags

New post 30 Aug 2017, 11:19
4 KUDOS received
Board of Directors
User avatar
V
Status: Stepping into my 10 years long dream
Joined: 18 Jul 2015
Posts: 3686
Premium Member Reviews Badge CAT Tests
Re: Networks of blood vessels in bats' wings serve only to disperse heat g [#permalink]

Show Tags

New post 30 Aug 2017, 11:43
4
gmatexam439 wrote:
GMATNinja abhimahna GMATNinjaTwo

Please explain why "E" is wrong and why "A" is correct? Also, please give the correct negation of each option.

Regards


Hi gmatexam439 ,

Here I go :

The passage says

1) Vessels serve ONLY to disperse heat.
2) Heat is generated ONLY while flapping wings.

=> I flap my wings, heat is generated and now it MUST disperse out of my vessels.

Then it concludes, since dinosaurs had these vessels therefore they used to flew.

Come on! This is non sense. Having some body part doesn't mean we are going to use it, right? What if they had those features but they never used it?

Hence, my pre thinking assumption is If THEY have a body feature, they have to use it anyhow.

Statement A is doing the same. Let's negate it.

They have had networks even if they don't use it. Ohh WOW, my conclusion is broken. How dare author say they used to fly? Call him, I wanna talk to him. :)

Moving on to option E.

(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 are already told that heat generated is dispersed ONLY by vessels. So, saying the same thing in different manner won't do any benefit. E can never be the answer.

Let's negate it.

Heat generated could be dispersed by other things too. Come on!! I am trying to break my premise. I cannot do so. (Look at the implication I drew after writing my two premises above.)

Hence, E is 100% wrong.

Does that make sense?
_________________

My GMAT Story: From V21 to V40
My MBA Journey: My 10 years long MBA Dream
My Secret Hacks: Best way to use GMATClub | Importance of an Error Log!
Verbal Resources: All SC Resources at one place | All CR Resources at one place
Blog: Subscribe to Question of the Day Blog

GMAT Club Inbuilt Error Log Functionality - View More.
New Visa Forum - Ask all your Visa Related Questions - here.

New! Best Reply Functionality on GMAT Club!



Find a bug in the new email templates and get rewarded with 2 weeks of GMATClub Tests for free

Manager
Manager
avatar
P
Joined: 17 May 2017
Posts: 144
GPA: 3
Reviews Badge
Re: Networks of blood vessels in bats' wings serve only to disperse heat g [#permalink]

Show Tags

New post 31 Aug 2017, 23:18
Someone please explain Why B and D are wrong confused here :(
Expert Post
1 KUDOS received
GMAT Club Verbal Expert
User avatar
P
Status: GMAT and GRE tutor
Joined: 13 Aug 2009
Posts: 1824
Location: United States
GMAT 1: 780 Q51 V46
GMAT 2: 800 Q51 V51
GRE 1: Q170 V170
Re: Networks of blood vessels in bats' wings serve only to disperse heat g [#permalink]

Show Tags

New post 02 Sep 2017, 00:51
1
haardiksharma wrote:
Someone please explain Why B and D are wrong confused here :(

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

It doesn't matter whether all creatures that fly by flapping their wings have networks of blood vessels in the skin of their wings. The author is simply arguing that the discovery "provides evidence for the hypothesis that Sandactylus flew by flapping its wings." For example, not EVERYONE who has a fancy car has a lot of money. However, having a fancy sports car can still be evidence that someone has a lot of money.

Quote:
D. If Sandactylus flew by flapping its wings, then paleontologists would certainly be able to find some evidence that it did so.

If choice (D) were not true, we would have: "If Sandactylus flew by flapping its wings, then paleontologists might be able to find some evidence that it did so." The author argues that the discovery provides evidence for the hypothesis that Sandactylus flew by flapping its wings. This argument does not require that, if Sandactylus did in fact fly by flapping its wings, paleontologists would DEFINITELY find evidence that it did so. (D) is not a required assumption.

I hope this helps!
_________________

GMAT Club Verbal Expert | GMAT/GRE tutor @ www.gmatninja.com (Now hiring!) | GMAT blog | Food blog | Notoriously bad at PMs

Beginners' guides to GMAT verbal
Reading Comprehension | Critical Reasoning | Sentence Correction

YouTube LIVE verbal webinars
Series 1: Fundamentals of SC & CR | Series 2: Developing a Winning GMAT Mindset

SC & CR Questions of the Day (QOTDs), featuring expert explanations
All QOTDs | Subscribe via email | RSS

Need an expert reply?
Hit the request verbal experts' reply button -- and please be specific about your question. Feel free to tag @GMATNinja and @GMATNinjaTwo in your post. Priority is always given to official GMAT questions.

Sentence Correction articles & resources
How to go from great (760) to incredible (780) on GMAT SC | That "-ing" Word Probably Isn't a Verb | That "-ed" Word Might Not Be a Verb, Either | No-BS Guide to GMAT Idioms | "Being" is not the enemy | WTF is "that" doing in my sentence?

Reading Comprehension, Critical Reasoning, and other articles & resources
All GMAT Ninja articles on GMAT Club | Using LSAT for GMAT CR & RC |7 reasons why your actual GMAT scores don't match your practice test scores | How to get 4 additional "fake" GMAT Prep tests for $29.99 | Time management on verbal

Senior Manager
Senior Manager
avatar
G
Joined: 26 Dec 2015
Posts: 277
Location: United States (CA)
Concentration: Finance, Strategy
WE: Investment Banking (Venture Capital)
Re: Networks of blood vessels in bats' wings serve only to disperse heat g [#permalink]

Show Tags

New post 04 Oct 2017, 11:47
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?

* ASSUMPTION Q. First, ID Conclusion: 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
- THEN, negate A/C to BREAK Conclusion

(A) Sandactylus would not have had networks of blood vessels in the skin of its wings if these networks were of no use to Sandactylus.
- S would still have these network of blood vessels regardless of whether or not they worked...this BREAKS the idea that S flew by flapping its wings.

(B) Not All creatures that fly by flapping their wings have networks of blood vessels in the skin of their wings.
- Not concerned with "all creatures". also, "not all" could mean 1 or 99% of creatures. Unsure where S falls here.

(C) Winged dinosaurs that flapped their wings in flight would not have been able to fly more effectively than winged dinosaurs that could only glide.
- Out of scope - who cares about flying effectively?

(D) If Sandactylus flew by flapping its wings, then paleontologists would certainly not be able to find some evidence that it did so.
- Out of scope. Does not address networks of blood vessels or the dispersion of heat generated by flight.

(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.
- Out of scope. Do not care about other ways to disperse heat...what do blood vessels do?

Kudos please if you find this helpful :)
Senior Manager
Senior Manager
avatar
B
Joined: 17 Sep 2016
Posts: 285
Re: Networks of blood vessels in bats' wings serve only to disperse heat g [#permalink]

Show Tags

New post 02 Apr 2018, 06:24
Quote:
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 Sandactylus.

(B) Not 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 wings in flight would not 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 not be able to find some 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.


Hi mikemcgarry, GMATNinjaTwo, GMATNinja, MagooshExpert Carolyn, sayantanc2,VeritasPrepKarishma
it took me many hours to review this question.

First, i have no idea where is my reasoning wrong?
(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.

E is bit complex, i simplify E,
flapping generats heat, and the heat CANNOT be dispersed without blood vessels.
in other word, no blood vessel , no dispersed heat.
it meants blood vessel is necessary to dispersed heat generated by Sandactylus in flapping.
because Sandactylus has blood vessel, so it can disperse heat generated in flapping, then provide the evidence that sandactylus flew by flapping its wings,not just by gliding.

second
if negate E,
(E) Heat generated by Sandactylus in flapping its wings in flight could not COULD have been dispersed by anything other than the blood vessels in its wings.
then negative (E) means there are other ways to disperse the heat generated by flapping.
so whether sandactylus has blood vessels does not provide evidence for the hypothesis,
Does it weaken ?
I think it does weaken.

BUT E is incorrect.

I think i must be wrong, but i have no idea where.
Please point out.

mostly, Assumption questions cost me lots of time and energy and i barely get right choice.

Genuinely your help.

Have a nice day
>_~
Expert Post
GMAT Club Verbal Expert
User avatar
S
Joined: 20 Nov 2016
Posts: 284
CAT Tests
Re: Networks of blood vessels in bats' wings serve only to disperse heat g [#permalink]

Show Tags

New post 02 Apr 2018, 07:59
zoezhuyan wrote:
Quote:
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 Sandactylus.

(B) Not 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 wings in flight would not 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 not be able to find some 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.


Hi mikemcgarry, GMATNinjaTwo, GMATNinja, MagooshExpert Carolyn, sayantanc2,VeritasPrepKarishma
it took me many hours to review this question.

First, i have no idea where is my reasoning wrong?
(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.

E is bit complex, i simplify E,
flapping generats heat, and the heat CANNOT be dispersed without blood vessels.
in other word, no blood vessel , no dispersed heat.
it meants blood vessel is necessary to dispersed heat generated by Sandactylus in flapping.
because Sandactylus has blood vessel, so it can disperse heat generated in flapping, then provide the evidence that sandactylus flew by flapping its wings,not just by gliding.

second
if negate E,
(E) Heat generated by Sandactylus in flapping its wings in flight could not COULD have been dispersed by anything other than the blood vessels in its wings.
then negative (E) means there are other ways to disperse the heat generated by flapping.
so whether sandactylus has blood vessels does not provide evidence for the hypothesis,
Does it weaken ?
I think it does weaken.

BUT E is incorrect.

I think i must be wrong, but i have no idea where.
Please point out.

mostly, Assumption questions cost me lots of time and energy and i barely get right choice.

Genuinely your help.

Have a nice day
>_~

zoezhuyan, stay tuned for a full QOTD explanation for this question later this month! In the meantime, we'll let the other experts and users weigh in :-)
_________________

www.gmatninja.com

Expert Post
GMAT Club Legend
GMAT Club Legend
User avatar
P
Joined: 16 Oct 2010
Posts: 8125
Location: Pune, India
Re: Networks of blood vessels in bats' wings serve only to disperse heat g [#permalink]

Show Tags

New post 02 Apr 2018, 09:24
zoezhuyan wrote:
Quote:
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 Sandactylus.

(B) Not 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 wings in flight would not 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 not be able to find some 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.


Hi mikemcgarry, GMATNinjaTwo, GMATNinja, MagooshExpert Carolyn, sayantanc2,VeritasPrepKarishma
it took me many hours to review this question.

First, i have no idea where is my reasoning wrong?
(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.

E is bit complex, i simplify E,
flapping generats heat, and the heat CANNOT be dispersed without blood vessels.
in other word, no blood vessel , no dispersed heat.
it meants blood vessel is necessary to dispersed heat generated by Sandactylus in flapping.
because Sandactylus has blood vessel, so it can disperse heat generated in flapping, then provide the evidence that sandactylus flew by flapping its wings,not just by gliding.

second
if negate E,
(E) Heat generated by Sandactylus in flapping its wings in flight could not COULD have been dispersed by anything other than the blood vessels in its wings.
then negative (E) means there are other ways to disperse the heat generated by flapping.
so whether sandactylus has blood vessels does not provide evidence for the hypothesis,
Does it weaken ?
I think it does weaken.

BUT E is incorrect.

I think i must be wrong, but i have no idea where.
Please point out.

mostly, Assumption questions cost me lots of time and energy and i barely get right choice.

Genuinely your help.

Have a nice day
>_~



Not sure if you have seen my previous post which discusses exactly why (E) is not the answer. Let me give it again here:

let's try to understand how the argument is structured. I will use variables to make it easier:

Networks of blood vessels in wings - A
heat generated in flight by flapping wings - B

Given Argument:
Bats have A. Bats have B. A's only job is to get rid of B.
Dinos had A too. Hence, Dinos had B too.

What is the assumption? That A must have had a purpose in Dinos too (getting rid of B). You cannot have A without having a job for it. Just because Dinos had A, we are concluding that they must have had B too. We are assuming that A must have had a purpose. This is option (A) and is the answer.

Are we assuming that we cannot get rid of B without A? No. (This is what option (E) says)
When would this be the assumption?
If the argument were a little different: Dinos had B. Hence, Dinos had A too.
In this argument, we are assuming that presence of B implies presence of A to get rid of B. The assumption is that we cannot get rid of B without A.
But given the original argument, this is not the assumption. Hence, answer is not (E).


Does this help?
_________________

Karishma
Private Tutor for GMAT
Contact: bansal.karishma@gmail.com

Senior Manager
Senior Manager
avatar
B
Joined: 17 Sep 2016
Posts: 285
Re: Networks of blood vessels in bats' wings serve only to disperse heat g [#permalink]

Show Tags

New post 02 Apr 2018, 23:22
VeritasPrepKarishma wrote:
zoezhuyan wrote:
Quote:
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 Sandactylus.

(B) Not 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 wings in flight would not 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 not be able to find some 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.


Hi mikemcgarry, GMATNinjaTwo, GMATNinja, MagooshExpert Carolyn, sayantanc2,VeritasPrepKarishma
it took me many hours to review this question.

First, i have no idea where is my reasoning wrong?
(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.

E is bit complex, i simplify E,
flapping generats heat, and the heat CANNOT be dispersed without blood vessels.
in other word, no blood vessel , no dispersed heat.
it meants blood vessel is necessary to dispersed heat generated by Sandactylus in flapping.
because Sandactylus has blood vessel, so it can disperse heat generated in flapping, then provide the evidence that sandactylus flew by flapping its wings,not just by gliding.

second
if negate E,
(E) Heat generated by Sandactylus in flapping its wings in flight could not COULD have been dispersed by anything other than the blood vessels in its wings.
then negative (E) means there are other ways to disperse the heat generated by flapping.
so whether sandactylus has blood vessels does not provide evidence for the hypothesis,
Does it weaken ?
I think it does weaken.

BUT E is incorrect.

I think i must be wrong, but i have no idea where.
Please point out.

mostly, Assumption questions cost me lots of time and energy and i barely get right choice.

Genuinely your help.

Have a nice day
>_~



Not sure if you have seen my previous post which discusses exactly why (E) is not the answer. Let me give it again here:

let's try to understand how the argument is structured. I will use variables to make it easier:

Networks of blood vessels in wings - A
heat generated in flight by flapping wings - B

Given Argument:
Bats have A. Bats have B. A's only job is to get rid of B.
Dinos had A too. Hence, Dinos had B too.

What is the assumption? That A must have had a purpose in Dinos too (getting rid of B). You cannot have A without having a job for it. Just because Dinos had A, we are concluding that they must have had B too. We are assuming that A must have had a purpose. This is option (A) and is the answer.

Are we assuming that we cannot get rid of B without A? No. (This is what option (E) says)
When would this be the assumption?
If the argument were a little different: Dinos had B. Hence, Dinos had A too.
In this argument, we are assuming that presence of B implies presence of A to get rid of B. The assumption is that we cannot get rid of B without A.
But given the original argument, this is not the assumption. Hence, answer is not (E).


Does this help?


Hi Karishma VeritasPrepKarishma
Frankly, I did read your explanation, and my interpretation is that , based on the discovery, the paleontologists conclude the hypothesis that Sandactylus flew by flapping, in other words, paleontologists fist got the discovery, then conclude a hypothesis from the discovery,
per your explanation, you point out a reverse logic that paleontologists first suppose Sandactylus did have heat generated from flapping if E is assumption, did i miss something or misunderstand?

When i reviewed this question yesteday, i tried to analyse E by myself, then new question came up,

Assumption is defined --an unstated evidence, without assumption, the author won't believe the conclusion is true.

E is bit complex, i simplify E,
flapping generats heat, and the heat CANNOT be dispersed without blood vessels.
in other word, no blood vessel , no dispersed heat, Am I right?
then, i think if Sandactylus has blood vessel, then they can dispersed the heat, right?
it meants blood vessel is necessary to dispersed heat generated by Sandactylus in flapping.
because Sandactylus has blood vessel, so it can disperse heat generated in flapping, then provide the evidence that sandactylus flew by flapping its wings,not just by gliding.

I am not sure where is incorrect.

If i use negative skill, then i think E break the argument.
(E) Heat generated by Sandactylus in flapping its wings in flight could not COULD have been dispersed by anything other than the blood vessels in its wings.

then negative (E) means there are other ways to disperse the heat generated by flapping.
so whether sandactylus has blood vessels does not provide evidence for the hypothesis,
Does it weaken ?
I think it does weaken.

Would you please point out the errors of my reasoning

Please ~~~


Have a nice day
>_~
Senior Manager
Senior Manager
avatar
B
Joined: 17 Sep 2016
Posts: 285
Re: Networks of blood vessels in bats' wings serve only to disperse heat g [#permalink]

Show Tags

New post 04 Apr 2018, 00:29
zoezhuyan wrote:
Hi Karishma VeritasPrepKarishma
Frankly, I did read your explanation, and my interpretation is that , based on the discovery, the paleontologists conclude the hypothesis that Sandactylus flew by flapping, in other words, paleontologists fist got the discovery, then conclude a hypothesis from the discovery,
per your explanation, you point out a reverse logic that paleontologists first suppose Sandactylus did have heat generated from flapping if E is assumption, did i miss something or misunderstand?

When i reviewed this question yesteday, i tried to analyse E by myself, then new question came up,

Assumption is defined --an unstated evidence, without assumption, the author won't believe the conclusion is true.


E is bit complex, i simplify E,
flapping generats heat, and the heat CANNOT be dispersed without blood vessels.
in other word, no blood vessel , no dispersed heat, Am I right?

then, i think if Sandactylus has blood vessel, then they can dispersed the heat, right?
it meants blood vessel is necessary to dispersed heat generated by Sandactylus in flapping.
because Sandactylus has blood vessel, so it can disperse heat generated in flapping, then provide the evidence that sandactylus flew by flapping its wings,not just by gliding.
I am not sure where is incorrect.

If i use negative skill, then i think E break the argument.
(E) Heat generated by Sandactylus in flapping its wings in flight could not COULD have been dispersed by anything other than the blood vessels in its wings.

then negative (E) means there are other ways to disperse the heat generated by flapping.
so the discovery that sandactylus has blood vessels does not provide evidence for the hypothesis,
Does it weaken ?
I think it does weaken.

Would you please point out the errors of my reasoning

Please ~~~


Have a nice day
>_~


Hi mikemcgarry, GMATNinjaTwo, GMATNinja, MagooshExpert Carolyn, @sayantanc2,@VeritasPrepKarishma
i think i got one of my reasoning problems , but new question came up , genuinely need you help to confirm.

here is my incorrect reasoning
because Sandactylus has blood vessel, so it can disperse heat generated in flapping, then provide the evidence that sandactylus flew by flapping its wings,not just by gliding.-- is incorrect.

Please check following
(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.

zoezhuyan wrote:
E is bit complex, i simplify E,
flapping generats heat, and the heat CANNOT be dispersed without blood vessels.
in other word, no blood vessel , no dispersed heat, Am I right?

up to there, i hold my reasoning

zoezhuyan wrote:
then, i think if Sandactylus has blood vessel, then they can dispersed the heat, right?
it meants blood vessel is necessary to dispersed heat generated by Sandactylus in flapping.
because Sandactylus has blood vessel, so it can disperse heat generated in flapping, then provide the evidence that sandactylus flew by flapping its wings,not just by gliding.

here, i think my reasoning --because Sandactylus has blood vessel, so it can disperse heat generated in flapping, then provide the evidence that sandactylus flew by flapping its wings,not just by gliding.-- is incorrect.
i reviewed the following
mikemcgarry wrote:
These are the words "necessary" and "sufficient." One way to say it is as follows:
"A is necessary for B." Here we know that if A doesn't happen, then B would not happen. If A does happen, then it may or may not be true that B can happen.


mikemcgarry wrote:
The word "sufficient" summaries the opposite relationship.
"A is sufficient for B." This means that if A happens, we know that B must be true; in other words, A is a guarantee for B. If A doesn't happen, then B may or may not be true.


so i think E is a necesary assumption, in other words, blood vessel is necessary assumption to dispersed heated generated by flapping
if sandactylus has blood vessels, it maybe dispered heated generated by flapping, maybe not.

So my rasoning is incorrect.

Wait a minute,a new problem,
according the stimulus, 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.
Can i then get that Sandaytlus can disperse heat generated in flapping, then provide the evidence that sandactylus flew by flapping its wings, not just by gliding ?

Further confused between assumption, necessary assumption.
Is necessary assumption a branch of assumption?
An assumption is unstated something that the author must believe to be true in order to draw a certain conclusion
Does it mean if the assumption happens, it can lead to the conclusion?
A is necessary for B, if A doesn't happen, then B would not happen.
necessary assumption is a branch of assumption?

i am still confused the following:
Quote:
I am not sure where is incorrect.

If i use negative skill, then i think E break the argument.
(E) Heat generated by Sandactylus in flapping its wings in flight could not COULD have been dispersed by anything other than the blood vessels in its wings.

then negative (E) means there are other ways to disperse the heat generated by flapping.
so the discovery that sandactylus has blood vessels does not provide evidence for the hypothesis,
Does it weaken ?
I think it does weaken.



All, please help,

Thank in advance
Have a nice day
>_~
Expert Post
GMAT Club Legend
GMAT Club Legend
User avatar
P
Joined: 16 Oct 2010
Posts: 8125
Location: Pune, India
Re: Networks of blood vessels in bats' wings serve only to disperse heat g [#permalink]

Show Tags

New post 04 Apr 2018, 04:08
zoezhuyan wrote:
Hi Karishma VeritasPrepKarishma
Frankly, I did read your explanation, and my interpretation is that , based on the discovery, the paleontologists conclude the hypothesis that Sandactylus flew by flapping, in other words, paleontologists fist got the discovery, then conclude a hypothesis from the discovery,
per your explanation, you point out a reverse logic that paleontologists first suppose Sandactylus did have heat generated from flapping if E is assumption, did i miss something or misunderstand?

When i reviewed this question yesteday, i tried to analyse E by myself, then new question came up,

Assumption is defined --an unstated evidence, without assumption, the author won't believe the conclusion is true.

E is bit complex, i simplify E,
flapping generats heat, and the heat CANNOT be dispersed without blood vessels.
in other word, no blood vessel , no dispersed heat, Am I right?
then, i think if Sandactylus has blood vessel, then they can dispersed the heat, right?
it meants blood vessel is necessary to dispersed heat generated by Sandactylus in flapping.
because Sandactylus has blood vessel, so it can disperse heat generated in flapping, then provide the evidence that sandactylus flew by flapping its wings,not just by gliding.

I am not sure where is incorrect.

If i use negative skill, then i think E break the argument.
(E) Heat generated by Sandactylus in flapping its wings in flight could not COULD have been dispersed by anything other than the blood vessels in its wings.

then negative (E) means there are other ways to disperse the heat generated by flapping.
so whether sandactylus has blood vessels does not provide evidence for the hypothesis,
Does it weaken ?
I think it does weaken.

Would you please point out the errors of my reasoning

Please ~~~


Have a nice day
>_~


We are on the same page - they did first discover blood vessels in wings. This discovery led to hypothesis - "they must be flying by flapping wings".
Think why? Just because they know that bats have blood vessels and the only purpose of those is to disperse heat generated by flapping wings in flight.
So they assumed that blood vessels in wings must have a purpose. They also assumed that the purpose must be the same as that in bats.

Did they have to assume that heat generated could not have been dispersed by any other way? No. That would have been your assumption had they found out that heat is generated by flapping and then tried to conclude that they MUST have had blood vessels. Here the assumption is that there is no other way to disperse heat.

By negating (E), you are discussing what happens when you KNOW that they generate heat by flapping wings. But we don't know that so it is irrelevant. Don't get lost in it.

See what happens when you negate (A) - Blood vessels may not have had a purpose. Then the whole conclusion falls apart.

Hence (A) is the answer.
_________________

Karishma
Private Tutor for GMAT
Contact: bansal.karishma@gmail.com

Re: Networks of blood vessels in bats' wings serve only to disperse heat g   [#permalink] 04 Apr 2018, 04:08

Go to page   Previous    1   2   [ 34 posts ] 

Display posts from previous: Sort by

Networks of blood vessels in bats' wings serve only to disperse heat g

  post reply Question banks Downloads My Bookmarks Reviews Important topics  

Events & Promotions

PREV
NEXT


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

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

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®.