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

It is currently 22 Oct 2019, 09:52

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

When the nineteenth-century German bacteriologist Robert Koch identifi

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

Hide Tags

Find Similar Topics 
Intern
Intern
avatar
Joined: 18 Aug 2014
Posts: 10
Location: India
Concentration: General Management, Finance
GMAT Date: 10-08-2014
GPA: 3.23
WE: Analyst (Retail Banking)
When the nineteenth-century German bacteriologist Robert Koch identifi  [#permalink]

Show Tags

New post Updated on: 17 Jan 2019, 01:43
7
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

68% (02:16) correct 32% (02:15) wrong based on 523 sessions

HideShow timer Statistics

When the nineteenth-century German bacteriologist Robert Koch identified a particular bacterium as responsible for cholera, Max von Pettenkoffer, a physician, expressed his skepticism by voluntarily drinking an entire bottle of the allegedly responsible bacteria. Although von Pettenkoffer took his failure to come down with the disease as a refutation of Koch's hypothesis that cholera was caused by bacteria, Koch argued that von Pettenkoffer had been protected by his own stomach acid. The acid secreted by the stomach, Koch explained, kills most ingested bacteria.

Which of the following, if true, provides the most evidence to support Koch's counterargument?


A. Peptic ulcers, often associated with excessive secretions of stomach acid, are common in certain areas characterized by low rates of cholera.

B. As von Pettenkoffer later admitted that he had previously had cholera, it is probable that he had developed antibodies that protected him from a second attack.

C. Cholera is endemic in areas in which poor sanitation results in high concentrations of cholera bacteria in drinking water.

D. Although stomach acid kills most ingested bacteria, large numbers of e. coli bacteria nonetheless manage to make their way to the lower intestine of the digestive tract.

E. Cholera bacteria ingested with bicarbonate of soda, a neutralizer of stomach acid, is more likely to result in cholera than if the bacteria is ingested alone.

_________________
The buttons on the left are the buttons you are looking for

Originally posted by Anamika2014 on 06 Sep 2014, 12:35.
Last edited by Bunuel on 17 Jan 2019, 01:43, edited 1 time in total.
Renamed the topic and edited the question.
Manager
Manager
User avatar
Joined: 21 Jul 2014
Posts: 119
GMAT ToolKit User
Re: When the nineteenth-century German bacteriologist Robert Koch identifi  [#permalink]

Show Tags

New post 06 Sep 2014, 13:03
1
Hi Anamika,

The best strategy to attack this question is to use Process of Elimination (PoE).

After reading the passage, we can see that Koch's counterargument is that von Pettenkoffer's stomach acid killed the ingested cholera bacteria resulting in him not getting infected.
We need to find which of the answer choices best supports this statement.

Answer choice A isn't relevant to this argument, so we can eliminate it.
Answer choice B provides an explanation for why von Pettenkoffer didn't get infected, but it doesn't support Koch's theory about stomach acid.
Answer choice C isn't relevant to this argument, so we can eliminate it.
Answer choice D talks about how stomach acid allows some bacteria to survive. This would weaken Koch's counterargument.
Answer choice E provides an alternative to neutralize the stomach acid and make infection more likely. This statement supports Koch's counterargument because it wouldn't allow the stomach acid to kill the cholera bacteria.

So, Answer Choice E is the only answer that supports Koch's argument.

Hope that helps! Good luck studying!

--------------
Lighthouse Prep
Intern
Intern
avatar
Joined: 28 Sep 2014
Posts: 15
D: M
GMAT 1: 700 Q49 V35
WE: Information Technology (Consulting)
Re: When the nineteenth-century German bacteriologist Robert Koch identifi  [#permalink]

Show Tags

New post 04 Apr 2016, 08:26
4
Though A is a strong contestant, A is not the answer because there is Koch never explained the more the acid is secreted the better a person is protected from cholera.

But E says that when a neutralizer of acid is added there is more chances of a person getting cholera which clearly is anevidence that acid kills the ingested bacteria.
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 58421
Re: When the nineteenth-century German bacteriologist Robert Koch identifi  [#permalink]

Show Tags

New post 17 Jan 2019, 01:44
Anamika2014 wrote:
When the nineteenth-century German bacteriologist Robert Koch identified a particular bacterium as responsible for cholera, Max von Pettenkoffer, a physician, expressed his skepticism by voluntarily drinking an entire bottle of the allegedly responsible bacteria. Although von Pettenkoffer took his failure to come down with the disease as a refutation of Koch's hypothesis that cholera was caused by bacteria, Koch argued that von Pettenkoffer had been protected by his own stomach acid. The acid secreted by the stomach, Koch explained, kills most ingested bacteria.

Which of the following, if true, provides the most evidence to support Koch's counterargument?


A. Peptic ulcers, often associated with excessive secretions of stomach acid, are common in certain areas characterized by low rates of cholera.

B. As von Pettenkoffer later admitted that he had previously had cholera, it is probable that he had developed antibodies that protected him from a second attack.

C. Cholera is endemic in areas in which poor sanitation results in high concentrations of cholera bacteria in drinking water.

D. Although stomach acid kills most ingested bacteria, large numbers of e. coli bacteria nonetheless manage to make their way to the lower intestine of the digestive tract.

E. Cholera bacteria ingested with bicarbonate of soda, a neutralizer of stomach acid, is more likely to result in cholera than if the bacteria is ingested alone.


KAPLAN OFFICIAL EXPLANATION:



E

After reading the stem for question 27, we go to the stimulus with eyes peeled for Koch's counterargument. Koch, we learn, is unconvinced by von Pettenkoffer's dramatic demonstration. When, after drinking a bottle of bacteria, von Pettenkoffer doesn't develop cholera, he claims to have proved that the bacterium doesn't cause cholera. Koch disagrees, saying that von Pettenkoffer's stomach acid killed the bacteria before it could affect him. Be careful; we don't want to strengthen Koch's original argument-that the bacterium causes cholera, but rather his second argument-that von Pettenkoffer's stomach acid killed the bacteria. (E) says that when the cholera bacteria is ingested with bicarbonate of soda, a stomach acid neutralize^ it's more likely that the person will develop the illness. (E), then, shows that acidity has an inhibiting effect on cholera bacteria, exactly as Koch argued.
_________________
GMAT Club Bot
Re: When the nineteenth-century German bacteriologist Robert Koch identifi   [#permalink] 17 Jan 2019, 01:44
Display posts from previous: Sort by

When the nineteenth-century German bacteriologist Robert Koch identifi

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





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