Each species of moth has an optimal body temperature for effective fli

Question

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 ______.

B. large moths are proportionally much more common in warm climates than in cool climates
This option talks about why more larger moth are present in warm climates compared to cool climates as larger moth has higher optimal temperatures -> Correct

(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

Minheequang · Accepted Answer

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 ______.

B. large moths are proportionally much more common in warm climates than in cool climates
This option talks about why more larger moth are present in warm climates compared to cool climates as larger moth has higher optimal temperatures -> Correct

A. large moths are generally able to maneuver better in flight than smaller moths -->  no info 
B. large moths are proportionally much more common in warm climates than in cool climates -->  best. Because of less vulnerable in warm climates than in cool climates, they are less likely to be eaten and thus proportionally more common in warm climates than in cool cliamtes 
C. small moths are more likely than large moths to be effectively camouflaged while on vegetation -->  no info about camouflage 
D. large moths typically have wings that are larger in proportion to their body size than smaller moths do -->  no info about size 
E. most predators of moths prey not only on several different species of moth but also on various species of other insects -->  irrelevant

ichha148 · Answer

I would go with B.

here is my explanation ,Though I am not good in explaining so pardon me in case i am not able to provide explanation clearly

Argument starts with describing relationship between optimal body temp and flying and role of air temp. Then the focus shifts to Large moths and the but also ... indicates that the author is giving a different perspective and B fits.

A. large moths are generally able to maneuver better in flight than smaller moths -large moths can fly faster however this does not go with the but also statement

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 - this doesn't make sense to me as there is no discussion on camouflaged
D. large moths typically have wings that are larger in proportion to their body size than smaller moths do - so what ? 
E. most predators of moths prey not only on several different species of moth but also on various species of other insects - this is not at all related

zaarathelab · Answer

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 ______.

B. large moths are proportionally much more common in warm climates than in cool climates
This option talks about why more larger moth are present in warm climates compared to cool climates as larger moth has higher optimal temperatures -> Correct

A. large moths are generally able to maneuver better in flight than smaller moths------- INCORRECT stimulus doesnt mention any relation between maneuvering and moths 
B. large moths are proportionally much more common in warm climates than in cool climates CORRECT. If larger moths have high optimal body temperatures they would be found more in warmer climates than in cooler climates as in cooler climates the differential temperature between their high optimal body temperature will be larger and hence they would have to remain inactive 
C. small moths are more likely than large moths to be effectively camouflaged while on vegetation  INCORRECT. This is a trap. Both would need camouflaging/or any other mechanism to escape predators while on vegetation irrespective of their flying abilities 
D. large moths typically have wings that are larger in proportion to their body size than smaller moths do INCORRECT. The relationship with larger wings and body temperature seems out of scope as it doesnt make any sense here 
E. most predators of moths prey not only on several different species of moth but also on various species of other insect INCORRECT. Out of scope

Hope this resolves the confusion between B and C

mojorising800 · Answer

i would go with B after POE..
A.Too extreme a sentence for the information provided int he text about the flight of the moths.
C.Camouflage not discussed.
D.Wing Size not discussed.
E.Other insects do not discussed.

fluke · Answer

"camouflaging" is not at all mentioned in the passage. I don't know where is this question from. But, "B" seems more plausible. Smaller moth-lower body temperature-relatively less warm climate is ideal.
Larger moth-higher body temperature-relatively higher warm climate is ideal, or they won't function as effectively.

You are right in noticing "but". "but" should show a contrast that rules out "A" as an answer. Also, "B" shows a reason why the higher body temperature is suited better for warmer climate, and we definitely need a reason "which explains why".

Ans: "B"
******************************

If anyone knows the source and OA for this question, please PM or reply to the post. thanks

Konstantin1983 · Answer

Hi naeln!
You have to find an answer that is compatible with an information given. Look at the answers. 
A. Do we know this? No this may be true or not true
B.  This is correct answer. If large moths have higher body temperature then it is likely that in warm climate live more large moths than live in cold climate. Just think in terms of their ability to escape from predators. In warm climate moths are better able to escape since here temperature is usually higher than in cold climate. Hence moths are better able to avoid flying predators 
C. We don't know about camouflage abilities.
D.Body temperature doesn't explain why large moths have wings that are larger in proportion
E.We don't know how body temperature relates to number of species that moths prey on. Even if large moths can fly faster how is it related with number of insects?
Hope it is clear

kinjiGC · Answer

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 ______.

B. large moths are proportionally much more common in warm climates than in cool climates
This option talks about why more larger moth are present in warm climates compared to cool climates as larger moth has higher optimal temperatures -> Correct

premise 1 : optimal body temperature for effective flight
premise 2 : larger moth more optimal temperature for flight.
The below option which explain the above premise:

A. large moths are generally able to  maneuver  better in flight than smaller moths
 We are not concerned about maneuvering aspect of the flight. we are just bothered about the relation between flight of larger moth and optimal temperature

B. large moths are proportionally much more common in warm climates than in cool climates
 This option talks about why more larger moth are present in warm climates compared to cool climates as larger moth has higher optimal temperatures -> Correct 
 
C. small moths are more likely than large moths to be effectively  camouflaged  while on vegetation
 We are not concerned about the "camouflage" aspect of the moth.

D. large moths typically  have wings that are larger  in proportion to their body size than smaller moths do
 We are not concerned about the larger wings of large moths.

E. most predators of moths  prey not only on several different species of moth but also on various species of other insects 
 We are not concerned about the prey aspect of the moths

akhil911 · Answer

Premise - Moths have optimal body temperature for effective flight and when the temperature drops the moths have to remain inactive - highly vulnerable to predators
Large moths can fly faster than small ones but they have higher optimal body temperatures.

If Large moths have higher optimal temperature then they would most commonly be found in areas which have relatively higher temperature.
If they live in areas which have lower temperature then they would be vulnerable to predators.
Only Option B supports this.

A. Large moths are generally able to maneuver better in flight than smaller moths
- There is no mention of maneuvering in the argument.
B. Large moths are proportionally much more common in warm climates than in cool climates
- Right choice for the reason stated above.
C. Small moths are more likely than large moths to be effectively camouflaged while on vegetation
- The argument does not mention anything about camouflaging.
D. Large moths typically have wings that are larger in proportion to their body size than smaller moths do
- The argument does not mention anything about wing size.
E. Most predators of moths prey not only on several different species of moth but also on various species of other insects
- There is no mention of other species

Kudos me if you like the post !!!

vishwaprakash · Answer

Moths - Inactive when temp falls below optimal Temp.
If inactive, then Moths are venerable and can be killed.

Optimal Temp of Big Moth is higher than Optimal temp of Small moth.
Big Moth Speed > Small moth's speed.

Pre thinking :
1. Big moth are More in numbers in warm whether since attackers will kill small one first.

A. Large moths are generally able to maneuver better in flight than smaller moths
Nice fact, but it is not supported by argument. Out of scope.

B. Large moths are proportionally much more common in warm climates than in cool climates
Correct matched Pre thinking. Supported by argument.

C. Small moths are more likely than large moths to be effectively camouflaged while on vegetation
Out of scope. This comparison has not been discussed in argument.

D. Large moths typically have wings that are larger in proportion to their body size than smaller moths do
Out of scope. Wings size not discussed

E. Most predators of moths prey not only on several different species of moth but also on various species of other insects
Out of scope. Predators taste is not discussed.

Answer : Option B

RaviChandra · Answer

kinjiGC  thanks for the explanation

I feel there is no Logically connectivity when B is plugged and the sentence is read as a whole.

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

Generally BUT is used to spot out contradictions : Ex: I walk very fast , but I cannot Run.

kanakdaga · Answer

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 ______.

B. large moths are proportionally much more common in warm climates than in cool climates
This option talks about why more larger moth are present in warm climates compared to cool climates as larger moth has higher optimal temperatures -> Correct

(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 -  CORRECT.  better chance of evading predators is only possible when larger moths can fly more effectively than the smaller ones. But larger moths have high optimal temperature so have to be more abundant in warmer climates for flying faster.

(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

emcheeks · Answer

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 ______.

B. large moths are proportionally much more common in warm climates than in cool climates
This option talks about why more larger moth are present in warm climates compared to cool climates as larger moth has higher optimal temperatures -> Correct

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

premise said that larger months can fly faster than smaller ones. However, fly faster ≠ maneuver better. For example, some people drive really fast, but that doesn't mean that they drive better (some fast-driving ppl get in to car accidents)

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

say there are moths in summer that survive longer. Moths in winter tend to die/be preyed --> More moths in summer and less in winter. Same logic could be applied to warm/cool climates as well.

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

"camouflaged" means that something is in disguise (when hide from prey etc.) However the stimulus didn't say anything about disguising. In addition, we know large moths fly faster to escape from predators, then in this case, larger moths might be more effective in disguising etc. C won't work and it disguising has nothing to do with body temperature.

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

unless it adds an explanation saying that somehow the wing size is related to the body temperatures, wing size is irrelevant.

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

"other insects" is irrelevant here.

GMATPolvon · Answer

Is it possible to make extra assumption as it has been done in reply B?

Engineer1 · Answer

KarishmaB   DmitryFarber   MartyMurray  Can anyone please review my thought process here? Thank you.

This is a strengthen and inference mixture question in my opinion.

Optimal body temp --> Effective flight 
But if external temp drops, body temp is impacted and hence, any species of moth's effectiveness of flight / ability to fly, leading to inactivity which further leads to vulnerability to predators. Small moths are impacted more than larger moths.

Larger moths fly faster and avoid predators comparatively better. However, they are still moths and their ability to fly is still impacted (more or less) due to lower external temperature. Since they have warmer body temp, the underlying assumption is that the drop in external temp has lower impact on larger moths.  What if the temp drops so low that it impairs the larger moths flight ability and throw them into inactive state of vegetation?  Something has to explain that this does not happen. How?

- Probably they have separate internal mechanism to keep their body temp at an optimal level irrespective of the external environment (a quality that smaller moths do not posses)?
I only had the above as a reason when I was analyzing the answer choices for some similar reasons.

A. If it impacts "maneuvering", the effectiveness is still impacted and they may still fall prey of predators. Eliminate
B. Still not an internal mechanism as I thought, but kept is aside for now
- Probably low external temp is still optimal for them (potentially warmer climate); an external factor that helps keep their body temp to optimal and they can fly faster, thereby saving themselves from predators.  CORRECT 
C. The question is asking about larger moths, not smaller ones. Eliminate.
D. I actually got stuck in this choice and took me a while to eliminate. 
 Yes, kind of internal mechanism and yes it may actually help them fly faster than smaller moths. But this has got nothing to do with body temperature. The answer choice has to prove that their body temp somehow stays optimal (or higher). Eliminate
E. This simply restates the first sentence of the argument. Eliminate

MartyMurray · Answer

It's really just a Conclusion question since the correct answer does not support a conclusion stated in the passage.

The passage does not say that small moths are "impacted more than larger moths" by the temperature.

The passage doesn't really say what you said. Rather it says the following:

In general, larger moths can fly faster than smaller ones ..., but they also  have higher optimal body temperatures

We see that the point is not that larger moths generally have higher body temperatures than smaller moths. The point is the optimal body temperature for larger moths is higher than the optimal body temperature for smaller moths.

So, what we can take away is, basically, that larger moths do better in warmer conditions.

So, because you misunderstood the passage, you went through the choices looking for the wrong thing.

The real issue with this choice is that it's not clearly related to optimal body temperature.

You ended up choosing this answer for basically the right reason even though your understanding of the passage was not correct.

Notice that this choice compares the larger moths with the smaller ones. So, it's about both types, meaning that your reason for eliminating it is incorrect.

Makes sense.

Not exactly, but this choice doesn't provide new information related to body temperature.

Takeaway:  Getting CR questions correct requires understanding the impacts of factors and constraints. In this case, it's key to understand what the passage is saying about "optimal body temperature" and what the implications of that information are.

Su1206 · Answer

Question does say that large moths can evade predators better than small moths. Doesnt that mean manevouring? I do agree B is better than A. But not able to digest A is wrong.

Each species of moth has an optimal body temperature for effective fli

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Each species of moth has an optimal body temperature for effective fli

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