Large Moths

This topic has expert replies
Master | Next Rank: 500 Posts
Posts: 239
Joined: Thu Oct 28, 2010 8:40 am
Location: India
Thanked: 5 times
Followed by:2 members
GMAT Score:690

Large Moths

by Dean Jones » Thu Jul 14, 2011 11:26 am
Hi Friends,

I am having difficulty with the follwoing question. Need help.

Which of the following most logically completes the passage?

Each species of moth has an optimal body temperature for effective flight, and when air temperatures fall much below that temperature, the moths typically have to remain inactive on vegetation for extended periods, leaving them highly vulnerable to predators. In general, larger moths can fly faster than smaller ones and hence have a better chance of evading flying predators, but they also have higher optimal body temperatures, which explains why ______.

A. large moths are generally able to maneuver better in flight than smaller moths

B. large moths are proportionally much more common in warm climates than in cool climates

C. small moths are more likely than large moths to be effectively camouflaged while on vegetation

D. large moths typically have wings that are larger in proportion to their body size than smaller moths do

E. most predators of moths prey not only on several different species of moth but also on various species of other insects


OA after some discussions.
Source: — Critical Reasoning |

User avatar
GMAT Instructor
Posts: 509
Joined: Wed Apr 21, 2010 1:08 pm
Location: Irvine, CA
Thanked: 199 times
Followed by:85 members
GMAT Score:750

by tpr-becky » Thu Jul 14, 2011 12:38 pm
Each species of moth has an optimal body temperature for effective flight, and when air temperatures fall much below that temperature, the moths typically have to remain inactive on vegetation for extended periods, leaving them highly vulnerable to predators. In general, larger moths can fly faster than smaller ones and hence have a better chance of evading flying predators, but they also have higher optimal body temperatures, which explains why ______.

if temp falls below body temperature Moths will be vulnerable to predators.
Large Moths fly faster but hive higer body temp.

Thus the inference is that large moths will be more vulnerable in lower temperatures because they have higher body temps.


A. large moths are generally able to maneuver better in flight than smaller moths
This is off topic and does not connect the two parts of the argument.
B. large moths are proportionally much more common in warm climates than in cool climates
This is a good answer because it shows that large moths do better evading predators in warm climates because they fly faster and do not drop below their body temp.
C. small moths are more likely than large moths to be effectively camouflaged while on vegetation
camouflaged is off topic.

D. large moths typically have wings that are larger in proportion to their body size than smaller moths do wing size is off topic.

E. most predators of moths prey not only on several different species of moth but also on various species of other insects this argument is about the large moths, not other species so this is off topic.
Becky
Master GMAT Instructor
The Princeton Review
Irvine, CA