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

It is currently 21 Oct 2014, 04:32

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:
Manager
Manager
avatar
Joined: 09 Jul 2010
Posts: 128
Followers: 0

Kudos [?]: 5 [0], given: 2

GMAT ToolKit User
Lyme disease is caused by a bacterium transmitted to humans [#permalink] New post 27 Feb 2012, 10:48
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  95% (hard)

Question Stats:

33% (02:03) correct 67% (01:58) wrong based on 39 sessions
Hi All

Could some one help with the cr question below. This is from the GMAT Prep CR.pdf document

Question 54: (S) 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 from feeding on infected white footed mice. However, certain other species on which the larvae feed do not harbor the bacterium. Therefore, if the population of these other species were increased, the number of ticks acquiring the bacterium and hence the number of people contracting Lyme disease would likely decline. Which of the following, if true, most strengthens the argument?
A. Ticks do not suffer any adverse consequences from carrying the bacterium that causes Lyme disease in humans.
B. There are no known cases of a human’s contracting Lyme disease through contact with white-footed mice.
C. A deer tick feeds only once while in the larval stage.
D. A single host animal can be the source of bacteria for many tick larvae.
E. None of the other species on which deer tick larvae feed harbor other bacteria that

I could not understand the answer choice
[Reveal] Spoiler: OA
Kaplan Promo CodeKnewton GMAT Discount CodesGMAT Pill GMAT Discount Codes
Verbal Forum Moderator
Verbal Forum Moderator
User avatar
Status: Flying over the cloud!
Joined: 16 Aug 2011
Posts: 818
Location: Viet Nam
Concentration: International Business, Marketing
Schools: Ross '17, Duke '16
GMAT Date: 06-06-2014
GPA: 3.07
Followers: 44

Kudos [?]: 238 [0], given: 43

GMAT ToolKit User Premium Member CAT Tests
Re: CR Quiestion [#permalink] New post 27 Feb 2012, 20:17
raviram80 wrote:
Hi All

Could some one help with the cr question below. This is from the GMAT Prep CR.pdf document

Question 54: (S) 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 from feeding on infected white footed mice. However, certain other species on which the larvae feed do not harbor the bacterium. Therefore, if the population of these other species were increased, the number of ticks acquiring the bacterium and hence the number of people contracting Lyme disease would likely decline. Which of the following, if true, most strengthens the argument?
A. Ticks do not suffer any adverse consequences from carrying the bacterium that causes Lyme disease in humans.
B. There are no known cases of a human’s contracting Lyme disease through contact with white-footed mice.
C. A deer tick feeds only once while in the larval stage.
D. A single host animal can be the source of bacteria for many tick larvae.
E. None of the other species on which deer tick larvae feed harbor other bacteria that

I could not understand the answer choice


First, you should comprehend the contend of the argument.

Dear ticks contain bacteria (Lyme disease) only in white footed mice, the other species that the dear ticks feed on them do not contain bacteria => Notice: All of the dear ticks are on larvae stage

Conclusion:
IF Other species increase, THEN ticks (have bacteria) & people (get the Lyme disease) will decline

The question is strengthen type. You can also use Negate technique. Negating choice C, If the deer ticks can feed on another stage beside larva stage => Ticks possibly develop on others animals and contain diseases. So, will weaken

=> Choice C is the correct one

Hope that helps
_________________

Rules for posting in verbal gmat forum, read it before posting anything in verbal forum
Giving me + 1 kudos if my post is valuable with you :)

The more you like my post, the more you share to other's need

CR: Focus of the Week: Must be True Question

Manager
Manager
avatar
Joined: 09 Jul 2010
Posts: 128
Followers: 0

Kudos [?]: 5 [0], given: 2

GMAT ToolKit User
Re: CR Quiestion [#permalink] New post 27 Feb 2012, 20:35
Thanks, still doubt

choice E says this

E. None of the other species on which deer tick larvae feed harbor other bacteria that can cause Lyme

What is wrong with this choice?
1 KUDOS received
Verbal Forum Moderator
Verbal Forum Moderator
User avatar
Status: Flying over the cloud!
Joined: 16 Aug 2011
Posts: 818
Location: Viet Nam
Concentration: International Business, Marketing
Schools: Ross '17, Duke '16
GMAT Date: 06-06-2014
GPA: 3.07
Followers: 44

Kudos [?]: 238 [1] , given: 43

GMAT ToolKit User Premium Member CAT Tests
Re: CR Quiestion [#permalink] New post 27 Feb 2012, 22:35
1
This post received
KUDOS
Choice E talks about other bacteria that also cause Lyme disease, but the argument talks about Lyme disease that is caused by only bacteria transmitted to human according to the argument. The other bacteria, we do not know how it can make human be disease. So, it is out of scope.

P/S: you should edit your choice E in the initial post to help other members see the full meaning. Thanks
_________________

Rules for posting in verbal gmat forum, read it before posting anything in verbal forum
Giving me + 1 kudos if my post is valuable with you :)

The more you like my post, the more you share to other's need

CR: Focus of the Week: Must be True Question

Verbal Forum Moderator
Verbal Forum Moderator
User avatar
Status: Flying over the cloud!
Joined: 16 Aug 2011
Posts: 818
Location: Viet Nam
Concentration: International Business, Marketing
Schools: Ross '17, Duke '16
GMAT Date: 06-06-2014
GPA: 3.07
Followers: 44

Kudos [?]: 238 [0], given: 43

GMAT ToolKit User Premium Member CAT Tests
Re: CR Quiestion [#permalink] New post 01 Mar 2012, 20:24
raviram80 wrote:
Thanks, still doubt

choice E says this

E. None of the other species on which deer tick larvae feed harbor other bacteria that can cause Lyme

What is wrong with this choice?


It will be better for me to clarify your mind if you show how do you think choice E is correct. Please, show me how :D.
_________________

Rules for posting in verbal gmat forum, read it before posting anything in verbal forum
Giving me + 1 kudos if my post is valuable with you :)

The more you like my post, the more you share to other's need

CR: Focus of the Week: Must be True Question

Expert Post
e-GMAT Representative
User avatar
Joined: 02 Nov 2011
Posts: 1794
Followers: 1298

Kudos [?]: 3662 [0], given: 185

Re: Lyme disease is caused by a bacterium transmitted to humans [#permalink] New post 11 Feb 2013, 02:25
Expert's post
Responding to a PM.

Question 54: (S) 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 from feeding on infected white footed mice. However, certain other species on which the larvae feed do not harbor the bacterium. Therefore, if the population of these other species were increased, the number of ticks acquiring the bacterium and hence the number of people contracting Lyme disease would likely decline. Which of the following, if true, most strengthens the argument?
A. Ticks do not suffer any adverse consequences from carrying the bacterium that causes Lyme disease in humans.
B. There are no known cases of a human’s contracting Lyme disease through contact with white-footed mice.
C. A deer tick feeds only once while in the larval stage.
D. A single host animal can be the source of bacteria for many tick larvae.
E. None of the other species on which deer tick larvae feed harbor other bacteria that ticks transmit to humans

I think, given the terminology and sentence structures used, this passage is not very easy to understand. Let's first understand the passage:

Understanding the passage:

1. Disease: Lyme
Caused by: bacteria
Source of bacteria: Deer ticks
2. Deer ticks pick the bacterium in their larva stage, from infected white footed mice
3. White footed mice is not the only food of Deer ticks - there is some food which does not contain this bacteria
4. Conclusion: If this 'other' food, which does not bacteria, is increased:
a. the number of deer ticks, who get bacteria, will reduce
b. the number of humans, who get infected by Lyme disease, will reduce

Prethinking:

If we read 3 & 4 together, we can see that the link between the premise and the conclusion is that once these deer ticks will have 'other' food to feed on, they'll stop or reduce eating white footed mice.

One more thing to observe, before we move on to the option analysis, is that there are two parts of the conclusion; therefore, a strengthener can strengthen either of these two parts.

Analysis of Answer Choices:

A. Ticks do not suffer any adverse consequences from carrying the bacterium that causes Lyme disease in humans - Whether Ticks suffer or not is not our concern here. This is Out of Scope.

B. There are no known cases of a human’s contracting Lyme disease through contact with white-footed mice - This means that humans acquire this from Deer Ticks only - same as first statement of the passage. No new information provided. Thus, this cannot be the correct choice. Incorrect.

C. A deer tick feeds only once while in the larval stage. - If a deer tick feeds only once in the larval stage, then once it has eaten something which is not infected, it'll not acquire the bacterium through this way. Therefore, if we increase the amount of uninfected feed, the probability that a larvae will eat uninfected feed will increase and therefore, its probablity of acquiring the bacterium will decrease. This, therefore, seems to strengthen the argument. For surity, let's also look at the remaining two choices.

D. A single host animal can be the source of bacteria for many tick larvae. - Whether a single host affects only one tick larvae or multiple larvae, it doesn't impact the conclusion at hand. Increasing the amount of uninfected feed should still decrease the probability of deer tick feeding on these infected mice.

E. None of the other species on which deer tick larvae feed harbor other bacteria that ticks transmit to humans - The issue is about Lyme disease only. Therefore, this is out of scope.

On the basis of our analysis, we can see that option C clearly emerges as the correct answer choice.

Hope this helps :)

Thanks,
Chiranjeev
_________________

https://www.youtube.com/watch?v=WeT9_Wr0DlI&feature=youtu.be

Intern
Intern
avatar
Joined: 01 Feb 2012
Posts: 16
Location: United States
Concentration: Finance, Strategy
GMAT 1: 640 Q49 V28
GMAT 2: 670 Q47 V35
GPA: 3.75
WE: Corporate Finance (Health Care)
Followers: 0

Kudos [?]: 8 [0], given: 4

Re: Lyme disease is caused by a bacterium transmitted to humans [#permalink] New post 11 Feb 2013, 06:18
Chranjeev and E-gmat

This definitely helped.

there is another version of this question
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.

Can we say that evaluate and strengthen is the same?
Also see my analysis on this one ( based on the the prethinking you did :)

A) Not relevant because even if other species is found in the area inhabited by white footed mice, it does not mean that other species will pick bacterium
B)Can be relevant - if the animals to feed on are not limited we cannot say that deer ticks larvae will move to other species. Lets park it
C) OFS, the conclusion is different than this solution
D)On first glance this looks relevant but than a careful read of the passage tells us that " deer ticks pick up the bacterium while in the larval stage" so they cannot pick up the infection as adults. Though I get the logic but i am still tempted by this choice and might pick this on test day becaue it in a way is saying that the plan of reducing the infectiong by introducing other species might not work ???
E) Any other bacteria is OFS

let me know if my analysis is correct and how can I definitely eliminate D? Would applying variance test work?

Thanks a lot
Expert Post
e-GMAT Representative
User avatar
Joined: 02 Nov 2011
Posts: 1794
Followers: 1298

Kudos [?]: 3662 [0], given: 185

Re: Lyme disease is caused by a bacterium transmitted to humans [#permalink] New post 11 Feb 2013, 08:51
Expert's post
scp wrote:
Chranjeev and E-gmat

This definitely helped.

there is another version of this question
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.

Can we say that evaluate and strengthen is the same?
Also see my analysis on this one ( based on the the prethinking you did :)

A) Not relevant because even if other species is found in the area inhabited by white footed mice, it does not mean that other species will pick bacterium
B)Can be relevant - if the animals to feed on are not limited we cannot say that deer ticks larvae will move to other species. Lets park it
C) OFS, the conclusion is different than this solution
D)On first glance this looks relevant but than a careful read of the passage tells us that " deer ticks pick up the bacterium while in the larval stage" so they cannot pick up the infection as adults. Though I get the logic but i am still tempted by this choice and might pick this on test day becaue it in a way is saying that the plan of reducing the infectiong by introducing other species might not work ???
E) Any other bacteria is OFS

let me know if my analysis is correct and how can I definitely eliminate D? Would applying variance test work?

Thanks a lot


Hi Scp,

You are correct that Choice D is indeed tempted. However, that is so till the time we don't understand the nuances of the passage and the conclusion. Let's understand this:

".... so the number of ticks acquiring the bacterium would likely decline" - If we eliminate one way of acquiring infection, wouldn't "incidence of infection" likely decline - even if there are other ways of acquiring infection (as suggested by option D. Option D, though tempting, doesn't really effect the conclusion.

Besides, if we read the passage, it says that "...Generally, deer ticks pick up the bacterium while in the larval stage..." - this means that getting infected at larvae stage is one of the most common ways to acquire infection. Thus, eliminating this should surely help.

Now, why option B is correct?

This is because it asks us to know the presence of any preference of deer ticks towards white footed mouse.

(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.

If the answer is yes, then it means that deer ticks probably eat white footed mice due to lack of other food and if that other food is increased, they will probably stop eating these infected mice. Therefore, the conclusion will hold.

If the answer is No, then it means that deer ticks eat these white footed mice in spite of other abundant food, so these deer ticks probably have some preference for these mice - therefore, increasing other food might not help. Therefore, the conclusion will not hold.

Hope this helps :)

-Chiranjeev
_________________

https://www.youtube.com/watch?v=WeT9_Wr0DlI&feature=youtu.be

Expert Post
Veritas Prep GMAT Instructor
User avatar
Joined: 16 Oct 2010
Posts: 4876
Location: Pune, India
Followers: 1150

Kudos [?]: 5348 [0], given: 165

Re: Lyme disease is caused by a bacterium transmitted to humans [#permalink] New post 11 Feb 2013, 20:34
Expert's post
scp wrote:
Chranjeev and E-gmat

This definitely helped.

there is another version of this question
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.

Can we say that evaluate and strengthen is the same?
Also see my analysis on this one ( based on the the prethinking you did :)

A) Not relevant because even if other species is found in the area inhabited by white footed mice, it does not mean that other species will pick bacterium
B)Can be relevant - if the animals to feed on are not limited we cannot say that deer ticks larvae will move to other species. Lets park it
C) OFS, the conclusion is different than this solution
D)On first glance this looks relevant but than a careful read of the passage tells us that " deer ticks pick up the bacterium while in the larval stage" so they cannot pick up the infection as adults. Though I get the logic but i am still tempted by this choice and might pick this on test day becaue it in a way is saying that the plan of reducing the infectiong by introducing other species might not work ???
E) Any other bacteria is OFS

let me know if my analysis is correct and how can I definitely eliminate D? Would applying variance test work?

Thanks a lot


Great analysis by Chiranjeev above. Let me add my thoughts on why (D) is not correct.

Given premise: Generally, deer ticks pick up the bacterium while in the larval stage by feeding on infected white-footed mice.

We assume this to be true. Generally, the ticks pick up bacterium in larval stage, not as adults. We don't need to evaluate whether the ticks can become infected as adults since we know that they generally pick up the bacterium at larval stage. Even if, in some rare cases, they can become infected in adulthood, there is no stopping that from happening right now too. So if out of 100 infected ticks, 95 get infected at larval stage and 5 during adulthood, the same may continue later too. Evaluating whether they can catch the infection during adulthood will not help. What we need to evaluate is whether we can decrease this number of infected ticks (100) by giving them some alternative food source.
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Save $100 on Veritas Prep GMAT Courses And Admissions Consulting
Enroll now. Pay later. Take advantage of Veritas Prep's flexible payment plan options.

Veritas Prep Reviews

Re: Lyme disease is caused by a bacterium transmitted to humans   [#permalink] 11 Feb 2013, 20:34
    Similar topics Author Replies Last post
Similar
Topics:
25 Experts publish their posts in the topic Lyme disease is caused by a bacterium transmitted to humans AndersonBound 68 21 Jul 2009, 21:18
2 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  


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®.