CR - Researchers studying the spread of the Black Plague

This topic has expert replies
Junior | Next Rank: 30 Posts
Posts: 24
Joined: Mon Jul 05, 2010 11:35 pm
Thanked: 1 times
Researchers studying the spread of the Black Plague in sixteenth-century England claim that certain people survived the epidemic because they carried a genetic mutation, known as Delta-32, that is known to prevent the bacteria that causes the Plague from overtaking the immune system. To support this hypothesis, the researchers tested the direct descendants of the residents of an English town where an unusually large proportion of people survived the Plague. More than half of these descendants tested positive for the mutation Delta-32, a figure nearly three times higher than that found in other locations.

The researchers' hypothesis is based on which of the following assumptions?
Delta-32 does not prevent a carrier from contracting any disease other than the Plague.
The Plague is not similar to other diseases caused by bacteria.
Delta-32 did not exist in its current form until the sixteenth century.
No one who tested positive for Delta-32 has ever contracted a disease caused by bacteria.
The Plague does not cause genetic mutations such as Delta-32.


The OA is E.
Source: — Critical Reasoning |

User avatar
Legendary Member
Posts: 1261
Joined: Sun Sep 14, 2008 3:46 am
Thanked: 27 times
GMAT Score:570

by reply2spg » Wed Sep 15, 2010 7:19 pm
This is cause and effect type of question. E shows that reverse is not possible and if it is then conclusion will not valid. Therefore, E is correct.
Sudhanshu
(have lot of things to learn from all of you)