It is currently 18 Feb 2018, 12:11

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

New research by Paul Fildes and K. Whitaker

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

Hide Tags

2 KUDOS received
Verbal Forum Moderator
User avatar
V
Status: Greatness begins beyond your comfort zone
Joined: 08 Dec 2013
Posts: 1908
Location: India
Concentration: General Management, Strategy
Schools: Kelley '20, ISB '19
GPA: 3.2
WE: Information Technology (Consulting)
GMAT ToolKit User Reviews Badge CAT Tests
New research by Paul Fildes and K. Whitaker [#permalink]

Show Tags

New post 08 Sep 2016, 01:32
2
This post received
KUDOS
Question 1
00:00
A
B
C
D
E

Question Stats:

69% (02:23) correct 31% (02:10) wrong based on 93

HideShow timer Statistics

Question 2
00:00
A
B
C
D
E

Question Stats:

55% (00:51) correct 45% (00:55) wrong based on 83

HideShow timer Statistics

Question 3
00:00
A
B
C
D
E

Question Stats:

60% (00:54) correct 40% (01:12) wrong based on 85

HideShow timer Statistics

New research by Paul Fildes and K. Whitaker challenges the theory that strains of bacteria can be “trained” to mutate by withholding a metabolite necessary for their
regular function. In particular, they consider the case of bacteria typhosum, which needs tryptophan in order to reproduce. Earlier researchers had grown the bacteria in
a medium somewhat deficient in tryptophan and observed the growth of mutant strains of the bacteria which did not need tryptophan in order to reproduce.

Fildes and Whitaker argue that the withholding of tryptophan did not induce these mutant strains of bacteria. Rather, these mutants were already present in the original
sample of bacteria typhosum, albeit in a concentration too small to detect. In experimenting with the bacteria grown in agar cultures, they found that by plating out
huge quantities of the bacteria, one could locate mutant strains. Because of the possibility that the lack of uniformity of the agar cultures had in fact trained mutant strains,
they conducted similar experiments with liquid cultures and again found that mutant strains of the bacteria were present in the original sampling. From these experiments,
Fildes and Whitaker conclude that the mutants are of genetic origin and are not induced by environmental training. They asserted that the concentration of tryptophan is unrelated to the appearance of these mutants in the bacteria.

To confirm these results, Fildes and Whitaker used an innovative plating technique using pile fabrics, such as velvet or velveteen, to accurately imprint the growth found
on an original agar plate to a series of replica agar plates. The process entails taking the original agar plate, inverting it onto the velvet while using light finger pressure to
transfer growth, and then imprinting the fabric, with its pattern of growth, on the new agar plates. By using this replica plating method, Fildes and Whitaker demonstrated
that the mutants were in fact genetically present or preadapted, as the locations of the mutant strains of bacteria on the replica plates were identical to the locations
of the mutant strains on the original agar plate.
1. According to the passage, Fildes and Whitaker conducted the experiment with liquid culture because
A. agar culture contained tryptophan
B. liquid culture allowed for easier plating
C. agar culture could not support a sufficiently large number of bacteria
D. liquid culture offered a more consistent medium
E. agar culture did not adhere well to pile fabric

[Reveal] Spoiler:
D


2. It can be inferred from the passage that the replica plating method is effective for which of the following reasons?
A. It allows researchers to determine the relative sizes of different populations of bacteria.
B. It shows that no new mutant strains developed after transfer from the original agar plate.
C. It eliminates the possibility that the agar culture was contaminated by a different type of bacteria.
D. It demonstrates that no tryptophan was present in the original agar culture.
E. It establishes that the original agar culture contained the necessary metabolites for bacterial reproduction.

[Reveal] Spoiler:
B


3. Which of the following most accurately states the purpose of the passage?
A. To defend a scientific hypothesis from attack by an innovative technique
B. To describe a process by which bacteria can be trained to mutate
C. To present the results of an experiment designed to test an established theory
D. To argue against an established protocol on the grounds that it is outdated
E. To challenge a scientific technique used to prove a questionable theory

[Reveal] Spoiler:
C

[Reveal] Spoiler: Question #1 OA
[Reveal] Spoiler: Question #2 OA
[Reveal] Spoiler: Question #3 OA

_________________

When everything seems to be going against you, remember that the airplane takes off against the wind, not with it. - Henry Ford
The Moment You Think About Giving Up, Think Of The Reason Why You Held On So Long
+1 Kudos if you find this post helpful


Last edited by Vyshak on 15 Sep 2016, 12:21, edited 1 time in total.
Added timer
Verbal Forum Moderator
User avatar
V
Status: Greatness begins beyond your comfort zone
Joined: 08 Dec 2013
Posts: 1908
Location: India
Concentration: General Management, Strategy
Schools: Kelley '20, ISB '19
GPA: 3.2
WE: Information Technology (Consulting)
GMAT ToolKit User Reviews Badge CAT Tests
Re: New research by Paul Fildes and K. Whitaker [#permalink]

Show Tags

New post 08 Sep 2016, 01:33

_________________

When everything seems to be going against you, remember that the airplane takes off against the wind, not with it. - Henry Ford
The Moment You Think About Giving Up, Think Of The Reason Why You Held On So Long
+1 Kudos if you find this post helpful

Verbal Forum Moderator
User avatar
V
Status: Greatness begins beyond your comfort zone
Joined: 08 Dec 2013
Posts: 1908
Location: India
Concentration: General Management, Strategy
Schools: Kelley '20, ISB '19
GPA: 3.2
WE: Information Technology (Consulting)
GMAT ToolKit User Reviews Badge CAT Tests
Re: New research by Paul Fildes and K. Whitaker [#permalink]

Show Tags

New post 08 Sep 2016, 01:34
6 mins 40 seconds , including 2 mins 50 seconds to read
_________________

When everything seems to be going against you, remember that the airplane takes off against the wind, not with it. - Henry Ford
The Moment You Think About Giving Up, Think Of The Reason Why You Held On So Long
+1 Kudos if you find this post helpful

Board of Directors
User avatar
V
Status: Aiming MBA
Joined: 18 Jul 2015
Posts: 3072
Location: India
Concentration: Healthcare, Technology
GPA: 3.65
WE: Information Technology (Health Care)
Premium Member Reviews Badge
Re: New research by Paul Fildes and K. Whitaker [#permalink]

Show Tags

New post 08 Sep 2016, 06:19
8 mins. DBC

Can someone please explain how can we reject choice E in question 2?
_________________

How I improved from V21 to V40! ?


How to use this forum in THE BEST way?

Top Contributor
Verbal Forum Moderator
avatar
Joined: 05 Nov 2012
Posts: 529
Concentration: Technology, Other
GMAT ToolKit User Premium Member Reviews Badge
Re: New research by Paul Fildes and K. Whitaker [#permalink]

Show Tags

New post 08 Sep 2016, 21:24
Top Contributor
7 mins all correct. Nice passage.
Regarding the query on Q2, why not E.

It can be inferred from the passage that the replica plating method is effective for which of the following reasons?
E) It establishes that the original agar culture contained the necessary metabolites for bacterial reproduction.

2:Fildes and Whitaker argue that the withholding of tryptophan did not induce these mutant strains of bacteria. Rather, these mutants were already present...Blah Blah
P3: To confirm these results, Fildes and Whitaker used an innovative plating technique using pile fabrics

Hope this answers your query.
_________________

--------------------------------------------------------
Regards :)

Senior Manager
Senior Manager
User avatar
P
Joined: 29 Jun 2017
Posts: 494
GMAT 1: 570 Q49 V19
GPA: 4
WE: Engineering (Transportation)
GMAT ToolKit User Premium Member Reviews Badge CAT Tests
Re: New research by Paul Fildes and K. Whitaker [#permalink]

Show Tags

New post 09 Jan 2018, 08:30
3min 58 sec for passage
3 min 24 sec for 3 questions
got ques 2 wrong , 2/3 correct :?
_________________

Give Kudos for correct answer and/or if you like the solution.

1 KUDOS received
Senior Manager
Senior Manager
User avatar
P
Joined: 29 Jun 2017
Posts: 494
GMAT 1: 570 Q49 V19
GPA: 4
WE: Engineering (Transportation)
GMAT ToolKit User Premium Member Reviews Badge CAT Tests
Re: New research by Paul Fildes and K. Whitaker [#permalink]

Show Tags

New post 09 Jan 2018, 08:52
1
This post received
KUDOS
abhimahna wrote:
8 mins. DBC

Can someone please explain how can we reject choice E in question 2?


May be its not required now - as you have already passed this phase.


By using this replica plating method, Fildes and Whitaker demonstrated
that the mutants were in fact genetically present or preadapted, as the locations of the mutant strains of bacteria on the replica plates were identical to the locationsof the mutant strains on the original agar plate.


Means => mutant did not develop after the transfer=> mutants were in fact genetically present or preadapted
B says this -> no new mutant strains developed after transfer from the original agar plate.

Lets see E-> It establishes that the original agar culture contained the necessary metabolites for bacterial reproduction.
outside info.


Anyways correct me- if you think my reasoning is wrong.
_________________

Give Kudos for correct answer and/or if you like the solution.

Re: New research by Paul Fildes and K. Whitaker   [#permalink] 09 Jan 2018, 08:52
Display posts from previous: Sort by

New research by Paul Fildes and K. Whitaker

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Terms and Conditions| 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®.