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

It is currently 31 Aug 2014, 00:47

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

Lyme disease is caused by a bacterium transmitted to humans

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
2 KUDOS received
Manager
Manager
avatar
Joined: 16 Feb 2009
Posts: 56
Schools: Anderson FEMBA
Followers: 0

Kudos [?]: 21 [2] , given: 1

Lyme disease is caused by a bacterium transmitted to humans [#permalink] New post 21 Jul 2009, 21:18
2
This post received
KUDOS
10
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

37% (02:36) correct 63% (01:53) wrong based on 175 sessions
Lyme disease is caused by a bacterium transmitted to humans by deer ticks. Generally, deer ticks pick up the bacterium while in the larval stage by feeding on infected white-footed mice. However, certain other species on which the larvae feed do not harbor the bacterium. If the population of these species increased, more of the larvae would be feeding on uninfected hosts, so the number of ticks acquiring the bacterium would likely decline.

Which of the following would it be most important to ascertain in evaluating the argument?

(A) Whether populations of the other species on which deer tick larvae feed are found only in the areas also inhabited by white-footed mice.
(B) Whether the size of the deer tick population is currently limited by the availability of animals for the tick's larval stage to feed on.
(C) Whether the infected deer tick population could be controlled by increasing the number of animals that prey on white-footed mice.
(D) Whether deer ticks that were not infected as larvae can become infected as adults by feeding on deer on which infected deer ticks have fed.
(E) Whether the other species on which deer tick larvae feed harbor any other bacteria that ticks transmit to humans.

[Had a really hard time understand the approach of the question and how to eliminate choices. Could only eliminate one answer choice. Any help / insight on how one could reach the actual answer????]

Last edited by AndersonBound on 21 Jul 2009, 23:22, edited 1 time in total.
5 KUDOS received
Intern
Intern
avatar
Joined: 04 Aug 2010
Posts: 22
Schools: Dartmouth College
Followers: 7

Kudos [?]: 29 [5] , given: 0

Re: tough CR: Lyme Disease [#permalink] New post 20 Aug 2010, 14:51
5
This post received
KUDOS
Lyme disease is caused by a bacterium transmitted to humans by deer ticks. Generally, deer ticks pick up the bacterium while in the larval stage by feeding on infected white-footed mice. However, certain other species on which the larvae feed do not harbor the bacterium. If the population of these species increased, more of the larvae would be feeding on uninfected hosts, so the number of ticks acquiring the bacterium would likely decline.

Which of the following would it be most important to ascertain in evaluating the argument?

Conclusion: If the population of the other species increased, the number of ticks acquiring the bacterium would decline.

Premises: The other species do not harbor the bacterium. The ticks generally acquire the bacterium while feeding in the larval stages.

Assumption: That the ticks will feed on the the other species if given the opportunity to do so.

Prediction: The correct answer will address the assumption and strengthen or weaken the conclusion. It will show whether the ticks actually will feed on the other species.

To understand the answer choices more easily, rephrase them without the word whether.

(A) The populations of the other species on which deer tick larvae feed are found only in the areas also inhabited by white-footed mice. Doesn't help us determine whether the ticks will feed on the other species.
(B) The size of the deer tick population is currently limited by the availability of animals for the tick's larval stage to feed on. Correct. This answer choice strengthens the conclusion: if the ticks don't currently have sufficient food, they are more likely to feed on the other species, reducing the number of infected ticks.
(C) The infected deer tick population could be controlled by increasing the number of animals that prey on white-footed mice. Outside the scope. The argument is not about how the population can be controlled but about whether the population would increase.
(D) The deer ticks that were not infected as larvae can become infected as adults by feeding on deer on which infected deer ticks have fed. Tempting, but incorrect. The argument states that the way the ticks generally get infected is by feeding in the larval stages. This is a premise of the argument and cannot be disputed. Any answer choice that discusses other ways the ticks can get infected is irrelevant. Even if ticks can get infected as adults, this is not the way ticks generally get infected, so who cares? A word of advice: an answer choice that attacks a premise will not be correct. The correct answer will address the assumption, which in this case is that the ticks will feed on the other species.
(E) Whether the other species on which deer tick larvae feed harbor any other bacteria that ticks transmit to humans. Out of scope. The argument isn't about other bacteria.

Hope this helps!

Mitch Hunt
GMAT tutor and instructor
New York, NY
_________________

GMAT Tutor and Instructor
GMATGuruNY@gmail.com
New York, NY

4 KUDOS received
Senior Manager
Senior Manager
avatar
Joined: 04 Jun 2008
Posts: 306
Followers: 5

Kudos [?]: 98 [4] , given: 15

GMAT Tests User
Re: tough CR: Lyme Disease [#permalink] New post 23 Jul 2009, 16:58
4
This post received
KUDOS
AndersonBound wrote:
Lyme disease is caused by a bacterium transmitted to humans by deer ticks. Generally, deer ticks pick up the bacterium while in the larval stage by feeding on infected white-footed mice. However, certain other species on which the larvae feed do not harbor the bacterium. If the population of these species increased, more of the larvae would be feeding on uninfected hosts, so the number of ticks acquiring the bacterium would likely decline.

Which of the following would it be most important to ascertain in evaluating the argument?

(A) Whether populations of the other species on which deer tick larvae feed are found only in the areas also inhabited by white-footed mice.
(B) Whether the size of the deer tick population is currently limited by the availability of animals for the tick's larval stage to feed on.
(C) Whether the infected deer tick population could be controlled by increasing the number of animals that prey on white-footed mice.
(D) Whether deer ticks that were not infected as larvae can become infected as adults by feeding on deer on which infected deer ticks have fed.
(E) Whether the other species on which deer tick larvae feed harbor any other bacteria that ticks transmit to humans.

[Had a really hard time understand the approach of the question and how to eliminate choices. Could only eliminate one answer choice. Any help / insight on how one could reach the actual answer????]


Good question.

B IMO

Say the size of deer tick is limited by availability of animals, ie, if there were more animals to feed upon, their would be more deer ticks, but because there is less food, population of deer ticks is limited. Then when uninfected food (animals) increases, uninfected deer tick population will increase.

However, if the deer tick already has sufficient food (infected or uninfected) there is no guarantee that the tick will feed on the extra uninfected animals. So no guarantee that extra uninfected animals will increase uninfected tick population.
2 KUDOS received
Director
Director
avatar
Status: Impossible is not a fact. It's an opinion. It's a dare. Impossible is nothing.
Affiliations: Chicago Booth Class of 2015
Joined: 26 Nov 2009
Posts: 995
Followers: 14

Kudos [?]: 393 [2] , given: 36

GMAT Tests User
Re: tough CR: Lyme Disease [#permalink] New post 09 Aug 2010, 22:48
2
This post received
KUDOS
In GMAT if any answer choice is asking you to bend backwards then probably its wrong - there will be herculean amount of thinking in 2 mins. That's not the technique used to crack.

D means many things hypothetically -
1) The infected number is going to first decrease and then at later point increase linearly causing the final number of infected ticks to remain the same
2) The infected number is going to decrease. Later time when the adults get infected the number is going to rise exponentially.
Basically D depends on lady luck and can take either sides. So D is not the answer. The most important thing is D is a shift in the focus of the argument.

nikhilkatira wrote:
nusmavrik wrote:
Food is the bone of contention between the ticks and the third species. We need to evaluate whether the method can limit the population of deer ticks. I hope you got B easily.

D is a scope shift. We are not here to ascertain the ultimate fate of the adolescent deer ticks. The argument here is to evaluate whether the method can limit the population of deer ticks based on the food they eat.

nikhilkatira wrote:
Agree that Option B is correct, but why is Option D incorrect ?


thanks for the explanation, but I am still getting little confused...please help me where am i getting wrong ?

The last sentence of the argument says"If the population of these species increased, more of the larvae would be feeding on uninfected hosts, so the number of ticks acquiring the bacterium would likely decline. "

So as per option D, what if ticks acquire bacterium after they become adults ?
The overall number will increase...

nusmavrik what am I missing ?

_________________

Please press kudos if you like my post.

1 KUDOS received
Manager
Manager
avatar
Joined: 15 Jun 2009
Posts: 165
Followers: 1

Kudos [?]: 19 [1] , given: 8

GMAT Tests User
Re: tough CR: Lyme Disease [#permalink] New post 23 Jul 2009, 01:28
1
This post received
KUDOS
AndersonBound wrote:
Lyme disease is caused by a bacterium transmitted to humans by deer ticks. Generally, deer ticks pick up the bacterium while in the larval stage by feeding on infected white-footed mice. However, certain other species on which the larvae feed do not harbor the bacterium. If the population of these species increased, more of the larvae would be feeding on uninfected hosts, so the number of ticks acquiring the bacterium would likely decline.

Which of the following would it be most important to ascertain in evaluating the argument?

(A) Whether populations of the other species on which deer tick larvae feed are found only in the areas also inhabited by white-footed mice. ....in the argument it is stated that "If the population of these species increased, more of the larvae would be feeding on uninfected hosts" ...it means that tehy are feeding on infected mice bcoz there is not enough unifected host...
(B) Whether the size of the deer tick population is currently limited by the availability of animals for the tick's larval stage to feed on....we r not concerned abt population
(C) Whether the infected deer tick population could be controlled by increasing the number of animals that prey on white-footed mice.......it cannot be inferrrd fom argument
(D) Whether deer ticks that were not infected as larvae can become infected as adults by feeding on deer on which infected deer ticks have fed. ...correct ...bocz if adult ticks can pick the bacteria from dear..then number of infected ticks will not decline.
(E) Whether the other species on which deer tick larvae feed harbor any other bacteria that ticks transmit to humans....out of scope

[Had a really hard time understand the approach of the question and how to eliminate choices. Could only eliminate one answer choice. Any help / insight on how one could reach the actual answer????]


IMO D....OA plz
Expert Post
1 KUDOS received
Kaplan GMAT Instructor
User avatar
Joined: 25 Aug 2009
Posts: 644
Location: Cambridge, MA
Followers: 67

Kudos [?]: 180 [1] , given: 2

GMAT Tests User
Re: tough CR: Lyme Disease [#permalink] New post 27 Nov 2009, 21:25
1
This post received
KUDOS
Expert's post
jjoon1979 wrote:
OA is B!

This question is from the prep, but I still don't understand why OA is B..
Take a look at my explanation a few posts back, and let me know if I can clear up any specific issues about it.
_________________

Eli Meyer
Kaplan Teacher
http://www.kaptest.com/GMAT

Prepare with Kaplan and save $150 on a course!

Image

Kaplan Reviews

Expert Post
1 KUDOS received
Kaplan GMAT Instructor
User avatar
Joined: 25 Aug 2009
Posts: 644
Location: Cambridge, MA
Followers: 67

Kudos [?]: 180 [1] , given: 2

GMAT Tests User
Re: tough CR: Lyme Disease [#permalink] New post 28 Nov 2009, 10:44
1
This post received
KUDOS
Expert's post
Good questions!

The larva of the tick "generally pick up the bacteria" from feeding on white footed mice--here, 'infected' and 'acquiring the bacteria' are synonyms.

So, if we have 1000 ticks feeding on the white-footed mice, we'll see infection. Some percentage of the mice will have the bacteria, and some percentage of the ticks feeding on those mice will acquire the bug. These percentages are a constant. So if 1000 ticks feeding on white-footed mice produce n infected ticks, then 500 will produce 1/2 n and 2000 will produce 2n. In other words, the plan is trying to reduce the number of infected ticks be reducing the number of ticks feeding on white-footed mice.

Since in the first case I described, introducing a non-carrier species for ticks to feed on would reduce the number of ticks drinking infected blood, but in the second case it would not, (B) is a central determinant to the success or failure of the plan. I hope that helps!
_________________

Eli Meyer
Kaplan Teacher
http://www.kaptest.com/GMAT

Prepare with Kaplan and save $150 on a course!

Image

Kaplan Reviews

1 KUDOS received
Intern
Intern
avatar
Joined: 10 Feb 2010
Posts: 34
Followers: 0

Kudos [?]: 1 [1] , given: 12

Re: tough CR: Lyme Disease [#permalink] New post 24 Jul 2010, 11:51
1
This post received
KUDOS
OA is B.
Attachments

v3.JPG
v3.JPG [ 108.56 KiB | Viewed 4629 times ]

1 KUDOS received
Manager
Manager
User avatar
Joined: 16 Jun 2010
Posts: 172
Followers: 3

Kudos [?]: 22 [1] , given: 1

Re: tough CR: Lyme Disease [#permalink] New post 28 Jul 2010, 00:16
1
This post received
KUDOS
rashminet84 wrote:
AndersonBound wrote:
Lyme disease is caused by a bacterium transmitted to humans by deer ticks. Generally, deer ticks pick up the bacterium while in the larval stage by feeding on infected white-footed mice. However, certain other species on which the larvae feed do not harbor the bacterium. If the population of these species increased, more of the larvae would be feeding on uninfected hosts, so the number of ticks acquiring the bacterium would likely decline.

Which of the following would it be most important to ascertain in evaluating the argument?

(A) Whether populations of the other species on which deer tick larvae feed are found only in the areas also inhabited by white-footed mice.
(B) Whether the size of the deer tick population is currently limited by the availability of animals for the tick's larval stage to feed on.
(C) Whether the infected deer tick population could be controlled by increasing the number of animals that prey on white-footed mice.
(D) Whether deer ticks that were not infected as larvae can become infected as adults by feeding on deer on which infected deer ticks have fed.
(E) Whether the other species on which deer tick larvae feed harbor any other bacteria that ticks transmit to humans.

[Had a really hard time understand the approach of the question and how to eliminate choices. Could only eliminate one answer choice. Any help / insight on how one could reach the actual answer????]


Good question.

B IMO

Say the size of deer tick is limited by availability of animals, ie, if there were more animals to feed upon, their would be more deer ticks, but because there is less food, population of deer ticks is limited. Then when uninfected food (animals) increases, uninfected deer tick population will increase.

However, if the deer tick already has sufficient food (infected or uninfected) there is no guarantee that the tick will feed on the extra uninfected animals. So no guarantee that extra uninfected animals will increase uninfected tick population.



Agree with B
_________________


R E S P E C T


Finally KISSedGMAT 700 times 450 to 700 An exprience

Manager
Manager
User avatar
Joined: 27 Jun 2008
Posts: 160
Followers: 2

Kudos [?]: 19 [0], given: 11

GMAT Tests User
Re: tough CR: Lyme Disease [#permalink] New post 21 Jul 2009, 22:46
Whats the statement of the problem?
Manager
Manager
avatar
Joined: 16 Feb 2009
Posts: 56
Schools: Anderson FEMBA
Followers: 0

Kudos [?]: 21 [0], given: 1

Re: tough CR: Lyme Disease [#permalink] New post 21 Jul 2009, 23:22
Oops. Updated. Thanks for the catch.
Intern
Intern
User avatar
Joined: 25 Nov 2007
Posts: 21
Followers: 0

Kudos [?]: 10 [0], given: 9

GMAT ToolKit User
Re: tough CR: Lyme Disease [#permalink] New post 22 Jul 2009, 01:07
Is OA A?

Firstly, by POE.
Secondly, "(A) Whether populations of the other species on which deer tick larvae feed are found only in the areas also inhabited by white-footed mice." because location of other species is important otherwise how would it be beneficial to increase the population of "other species" in some location while the deer ticks continue to feed on mice in another lcoation.

HTH.
Manager
Manager
User avatar
Joined: 12 Jul 2009
Posts: 59
Followers: 1

Kudos [?]: 4 [0], given: 9

Re: tough CR: Lyme Disease [#permalink] New post 22 Jul 2009, 01:52
B..i think
:arrow:
if the population of deer tick increases with addition of new species to feed, possibility of the disease increase further. The white mice population is not reduced anyway.
Intern
Intern
avatar
Joined: 06 Jul 2009
Posts: 33
Followers: 0

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

Re: tough CR: Lyme Disease [#permalink] New post 22 Jul 2009, 11:58
IMO - A

The argument states that if population of other species increased, the number of ticks w/ bacterium would decrease. By POE, answer should be A because knowing whether other species are in areas where white footed mice inhabit could support or weaken the argument.
Manager
Manager
avatar
Joined: 16 Feb 2009
Posts: 56
Schools: Anderson FEMBA
Followers: 0

Kudos [?]: 21 [0], given: 1

Re: tough CR: Lyme Disease [#permalink] New post 23 Jul 2009, 14:34
Someone has provided the right answer. :wink:

HOWEVER, there is enough disagreement between answers that I would like to see more discussion around the answer choices.

OA to follow soon enough.
Intern
Intern
avatar
Joined: 21 Jul 2009
Posts: 33
Followers: 9

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

Re: tough CR: Lyme Disease [#permalink] New post 23 Jul 2009, 15:36
AndersonBound wrote:
Lyme disease is caused by a bacterium transmitted to humans by deer ticks. Generally, deer ticks pick up the bacterium while in the larval stage by feeding on infected white-footed mice. However, certain other species on which the larvae feed do not harbor the bacterium. If the population of these species increased, more of the larvae would be feeding on uninfected hosts, so the number of ticks acquiring the bacterium would likely decline.

Which of the following would it be most important to ascertain in evaluating the argument?

(A) Whether populations of the other species on which deer tick larvae feed are found only in the areas also inhabited by white-footed mice.
(B) Whether the size of the deer tick population is currently limited by the availability of animals for the tick's larval stage to feed on.
(C) Whether the infected deer tick population could be controlled by increasing the number of animals that prey on white-footed mice.
(D) Whether deer ticks that were not infected as larvae can become infected as adults by feeding on deer on which infected deer ticks have fed.
(E) Whether the other species on which deer tick larvae feed harbor any other bacteria that ticks transmit to humans.

[Had a really hard time understand the approach of the question and how to eliminate choices. Could only eliminate one answer choice. Any help / insight on how one could reach the actual answer????]


Agree with A but largely through POE. Author's main argument: "If the population of these species [i.e., other species on which the larvae feed that do not harbor the bacterium] increased, more of the larvae would be feeding on uninfected hosts, so the number of ticks acquiring the bacterium would likely decline."

My personal logic for A may seem a bit of a stretch, but the first two sentences of the paragraph imply that the tick is the agent for transmitting the bacteria. If the non-infected species are living amongst the white-footed mice (and, as a result, the ticks that are feeding off of these infected mice), these other species are at risk of acquiring the bacterium and, as a result, at risk of becoming just like the bacterium-infected white-footed mice themselves.

Reasons why others seem to be good candidates for elimination:

B.) This one looks like a trap because of the way that "population" is used. The author is not concerned with the deer tick population size but rather the population size of non-infected other species.

C.) Same as B - argument says if population of non-infected species increased -> number of ticks acquiring the bacterium decline. Nothing to do with population size of deer ticks.

D.) There's no mention of deer in the paragraph, just deer ticks. Looks like another trap. Would be more enticing if it mentioned general other species instead of deer specifically.

E.) The author's not concerned with other bacteria, only Lime Disease bacterium. After the first sentence ("Lyme disease is caused by a bacterium transmitted to humans by deer ticks"), each subsequent mention of bacterium is preceded by "the", meaning he is referring to the specific bacterium mentioned in the first sentence. His argument/conclusion is regarding Lyme disease bacterium.

Now.. what's the OA? :)
Senior Manager
Senior Manager
User avatar
Joined: 10 Dec 2008
Posts: 484
Location: United States
GMAT 1: 760 Q49 V44
GPA: 3.9
Followers: 29

Kudos [?]: 117 [0], given: 12

GMAT Tests User
Re: tough CR: Lyme Disease [#permalink] New post 23 Jul 2009, 18:54
I don't know. B? :shock:
Manager
Manager
avatar
Joined: 10 Jul 2009
Posts: 172
Followers: 1

Kudos [?]: 33 [0], given: 8

GMAT Tests User
Re: tough CR: Lyme Disease [#permalink] New post 23 Jul 2009, 19:46
I would go for 'A'.
Please post the answer
Manager
Manager
avatar
Joined: 14 Jun 2009
Posts: 97
Followers: 2

Kudos [?]: 5 [0], given: 9

Re: tough CR: Lyme Disease [#permalink] New post 23 Jul 2009, 21:01
B...by POE :P
Intern
Intern
avatar
Joined: 21 Jul 2009
Posts: 33
Followers: 9

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

Re: tough CR: Lyme Disease [#permalink] New post 26 Jul 2009, 10:29
can we get the OA for this?
Re: tough CR: Lyme Disease   [#permalink] 26 Jul 2009, 10:29
    Similar topics Author Replies Last post
Similar
Topics:
1 Lyme disease is caused by a bacterium transmitted to humans lys8207 11 16 Oct 2009, 08:44
1 Lyme disease is caused by a bacterium transmitted to humans jjhko 7 20 Apr 2009, 18:17
Lyme disease is caused by a bacterium transmitted to humans vivek123 11 02 Mar 2006, 18:03
Lyme disease is caused by a bacterium transmitted to humans cybera 5 15 Jul 2005, 08:43
Lyme disease is caused by a bacterium transmitted to humans chunjuwu 8 18 Jan 2005, 04:19
Display posts from previous: Sort by

Lyme disease is caused by a bacterium transmitted to humans

  Question banks Downloads My Bookmarks Reviews Important topics  

Go to page    1   2   3   4    Next  [ 69 posts ] 



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®.