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# Insect-eating bats rely heavily on echolocation, a method of sensory p

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Insect-eating bats rely heavily on echolocation, a method of sensory p  [#permalink]

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Updated on: 17 Sep 2019, 02:46
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New Project RC Butler 2019 - Practice 2 RC Passages Everyday
Passage # 222, Date : 22-Jul-2019
This post is a part of New Project RC Butler 2019. Click here for Details

Insect-eating bats rely heavily on echolocation, a method of sensory perception by which certain animals orient themselves to their surroundings, detect obstacles, communicate with others, and find food. While using echolocation, these bats emit a series of short, high-frequency sounds from their mouths or nostrils that bounce off objects and surfaces and then return to the animals’ ears. Since high-frequency waves do not diffract, or bend, extensively, these ultrasonic vibrations provide bats with accurate maps of their surroundings. The biosonar of some bats is so advanced that it allows them to fly in complete darkness, snatch moving insects out of the air, or hover just above water level to drink.

For years, scientists have been aware that bats emit slightly different frequencies in differing situations. Recent research has provided insight into how certain physical features help bats use this variability to differentiate among objects in their environments. Many species of bats have elaborate, intricately shaped flaps, or noseleaves, around their nostrils that are adorned with grooves and spikes. Three-dimensional computer simulations of these noseleaves revealed that furrows along the top of the noseleaves act as cavities that resonate strongly with certain frequencies of sound. As a result, the grooves cause different frequencies of sound to discharge in different directions. Lower frequency sounds are spread more vertically, while higher frequency sounds emit more horizontally. The complexity the noseleaves add to the bats’ ultrasound perception could help the bats perform difficult tasks, such as locating prey while avoiding obstacles.
Spoiler: :: OA & OE
The first paragraph of the passage explains that bats use echolocation and broadly describes how echolocation works. The second paragraph explores the nuances of echolocation in bats, with a particular emphasis on the importance of noseleaves in certain bat species.

(A) A particular process – echolocation – is mentioned in the first paragraph. However, the second paragraph never discounts the complexity of this process. Instead, it expounds upon the complexity of this process.

(B) A biological system – echolocation – is discussed in the first paragraph. However, no debate over echolocation is mention in the second paragraph or anywhere else in the passage.

(C) CORRECT. The first paragraph does introduce a method: echolocation. The second paragraph then offers insight into, or illuminates, certain complexities of echolocation, such as how bats are able to utilize their noseleaves to emit differing frequencies.

(D) The first paragraph does not establish a hypothesis; instead, the first paragraph simply explains, in broad terms, the method of echolocation in bats.

(E) The second paragraph does describe the function of a particular physical feature: noseleaves. However, this feature is never mentioned in the first paragraph.

1. Which of the following best describes the relation of the second paragraph to the first paragraph?

(A) The second paragraph discounts the complexity of a process that is revealed in the first paragraph.
(B) The second paragraph clarifies a debate over a biological system that is discussed in the first paragraph.
(C) The second paragraph illuminates the intricacies of a method that is introduced in the first paragraph.
(D) The second paragraph explains the results of a hypothesis that is expressed in the first paragraph.
(E) The second paragraph describes the function of a physical feature that is mentioned in the first paragraph.

Spoiler: :: OA & OE
According to the passage, the purpose of the noseleaves is to help bats “perform difficult tasks, such as locating prey while avoiding obstacles.” The noseleaves do so by allowing bats to emit differing frequencies of sound in different directions. These sound waves “bounce off objects and surfaces and then return to the animals’ ears,” providing the bats with vital information about their surroundings. To weaken the conclusion about the purpose of noseleaves, we must demonstrate that they do not necessarily aid bats in accessing this vital information.

(A) CORRECT. For the noseleaves to contribute to the bats’ understanding of their surroundings, the bats must be able to interpret the information provided by the different frequencies of sound. According to this choice, the bats are emitting at various frequencies, but are “receiving” only a small percentage of what they emit. This idea weakens the conclusion that the noseleaves, by allowing bats to emit a greater range of frequencies, contribute to an enhanced awareness of the immediate environment.

(B) The fact that many bats emit sounds through their mouths does not weaken the conclusion concerning the purpose of noseleaves for those bats that do possess this distinctive feature.

(C) Dolphins live in an environment that is completely different from that of bats. Thus, it is not possible to draw definitive conclusions about the noseleaves of bats simply because dolphins lack such a feature.

(D) For several reasons, the fact that some bats rely on sight and smell does not undermine the conclusion about noseleaves. First, we do not know which bats act in this manner or whether these bats even possess noseleaves. Second, “some” is an ambiguous term; it could refer to a few species of bats rather than a large number. Finally, the passage implies that echolocation is most useful while bats are in motion and their prey is also in motion (echolocation allows bats to “snatch insects out of the air”). It is very possible that bats have alternative strategies when their sources of food are stationary.

(E) The limited range of echolocation does not undermine the purpose of the noseleaves. It is very possible that many “difficult” tasks must be accomplished within a short distance from where bats emit their signals.

2. Which of the following, if true, would most weaken the conclusion concerning the purpose of bats’ noseleaves?

(A) The range of frequencies that bats hear is much smaller than the range of frequencies that bats emit.
(B) Many bats emit echolocation sounds through their mouths rather than through their noses.
(C) Dolphins rely on echolocation, and they do not have noseleaves.
(D) When their food sources are stationary, some bats rely on eyesight and smell rather than echolocation.
(E) The sound waves emitted during echolocation are limited to a range of fewer than one hundred feet.

Spoiler: :: OA & OE
On the GMAT, the answer to an inference question must be directly supported by evidence from the text. As always, be sure to pay particular attention to the precise words used in the answer choices and how these words relate to the information presented in the passage.

(A) The second paragraph of the passage states that “lower frequency sounds are spread more vertically, while higher frequency sounds emit more horizontally” (lines 37-40). Thus, sound waves are emitted in a range of directions rather than just vertically and horizontally.

(B) The second paragraph of the passage relates the importance that the grooves found on noseleaves play in echolocation. No information is given concerning the role that the spikes play. Because we have no information about the spikes, we cannot infer anything about their role during echolocation.

(C) The passage does highlight the importance of echolocation, but it neither contrasts this ability with bats’ sense of sight nor even mentions the sense of sight. Thus, this answer choice is outside the scope of the passage.

(D) The first paragraph of the passage states that bats use high-frequency sound waves “since high-frequency waves do not diffract, or bend, extensively” (lines 11-13). Thus, it can be inferred that low-frequency sound waves diffract more than high-frequency sound waves.

(E) CORRECT. The first paragraph of the passage states that “while using echolocation, these bats emit a series of short, high-frequency sounds from their mouths or nostrils” (lines 6-8). Then, the first sentence of the second paragraph indicates that “bats emit slightly different frequencies in differing situations.” Taken together, these statements confirm that bats emit only high frequencies during echolocation. The variations in the sound waves' frequencies are slight, so that even the "lower frequency sounds" mentioned in lines 37-38 are within the range considered high-frequency.

3. Which of the following can properly be inferred from the passage?

(A) The sound waves a bat emits during echolocation only travel parallel or perpendicular to the bat's motion.
(B) The spikes found on bats’ noseleaves are rarely utilized during echolocation.
(C) Many insect-eating bats do not possess a well-developed sense of sight.
(D) Low-frequency sound waves diffract less extensively than high-frequency sound waves.
(E) During echolocation, bats do not rely on low-frequency sound waves.

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Originally posted by hazelnut on 13 Oct 2017, 00:59.
Last edited by SajjadAhmad on 17 Sep 2019, 02:46, edited 4 times in total.
Updated - Complete topic (560).
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Re: Insect-eating bats rely heavily on echolocation, a method of sensory p  [#permalink]

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17 Oct 2017, 14:15
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I got 3rd wrong , can anyone explain why C is wrong and E is right?
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Re: Insect-eating bats rely heavily on echolocation, a method of sensory p  [#permalink]

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18 Oct 2017, 11:29
1
Utkarsh KOhli wrote:
I got 3rd wrong , can anyone explain why C is wrong and E is right?

3. Which of the following can properly be inferred from the passage?

(A) The sound waves a bat emits during echolocation only travel parallel or perpendicular to the bat's motion.

(B) The spikes found on bats’ noseleaves are rarely utilized during echolocation.

(C) Many insect-eating bats do not possess a well-developed sense of sight. - Incorrect - passage only states that "The biosonar of some bats is so advanced that it allows them to fly in complete darkness, snatch moving insects out of the air, or hover just above water level to drink. "

(D) Low-frequency sound waves diffract less extensively than high-frequency sound waves.

(E) During echolocation, bats do not rely on low-frequency sound waves. -"While using echolocation, these bats emit a series of short, high-frequency sounds from their mouths or nostrils that bounce off objects and surfaces and then return to the animals’ ears."
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23 Jul 2019, 05:48
1
1) (C) The second paragraph illuminates the intricacies of a method that is introduced in the first paragraph.
In the first paragraph we have small explanation for the method: While using echolocation, these bats emit a series of short, high-frequency sounds from their mouths or nostrils that bounce off objects and surfaces and then return to the animals’ ears.
in the second paragraph we see detailed explanation for this metod, so, the answer is C

2) (A) The range of frequencies that bats hear is much smaller than the range of frequencies that bats emit.
if we accept this argument as true agrument, we will see that the bats can't create very detailed map, since they will loose responses So, this answer weakes the conclusion

3) (E) During echolocation, bats do not rely on low-frequency sound waves.
bats emit a series of short, high-frequency sounds from their mouths or nostrils (1st paragraph) so since they emit high-frequency sounds they do not rely on low-frequency sound waves
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Re: Insect-eating bats rely heavily on echolocation, a method of sensory p  [#permalink]

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02 Sep 2019, 23:30
1. Which of the following best describes the relation of the second paragraph to the first paragraph?

(A) The second paragraph discounts the complexity of a process that is revealed in the first paragraph.
(B) The second paragraph clarifies a debate over a biological system that is discussed in the first paragraph.
(C) The second paragraph illuminates the intricacies of a method that is introduced in the first paragraph.
(D) The second paragraph explains the results of a hypothesis that is expressed in the first paragraph.
(E) The second paragraph describes the function of a physical feature that is mentioned in the first paragraph.

Why E is incorrect ?
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Re: Insect-eating bats rely heavily on echolocation, a method of sensory p  [#permalink]

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03 Sep 2019, 05:00
Official Explanation

1. Which of the following best describes the relation of the second paragraph to the first paragraph?

Difficulty Level: 600

Explanation

The first paragraph of the passage explains that bats use echolocation and broadly describes how echolocation works. The second paragraph explores the nuances of echolocation in bats, with a particular emphasis on the importance of noseleaves in certain bat species.

(A) A particular process – echolocation – is mentioned in the first paragraph. However, the second paragraph never discounts the complexity of this process. Instead, it expounds upon the complexity of this process.

(B) A biological system – echolocation – is discussed in the first paragraph. However, no debate over echolocation is mention in the second paragraph or anywhere else in the passage.

(C) CORRECT. The first paragraph does introduce a method: echolocation. The second paragraph then offers insight into, or illuminates, certain complexities of echolocation, such as how bats are able to utilize their noseleaves to emit differing frequencies.

(D) The first paragraph does not establish a hypothesis; instead, the first paragraph simply explains, in broad terms, the method of echolocation in bats.

(E) The second paragraph does describe the function of a particular physical feature: noseleaves. However, this feature is never mentioned in the first paragraph.

Hope it helps

dharam44 wrote:
1. Which of the following best describes the relation of the second paragraph to the first paragraph?

(A) The second paragraph discounts the complexity of a process that is revealed in the first paragraph.
(B) The second paragraph clarifies a debate over a biological system that is discussed in the first paragraph.
(C) The second paragraph illuminates the intricacies of a method that is introduced in the first paragraph.
(D) The second paragraph explains the results of a hypothesis that is expressed in the first paragraph.
(E) The second paragraph describes the function of a physical feature that is mentioned in the first paragraph.

Why E is incorrect ?

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Re: Insect-eating bats rely heavily on echolocation, a method of sensory p  [#permalink]

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03 Sep 2019, 06:32
In ques # 3. Why the ans is not B.

A. waves are emitted in different directions. Rejected
B.
C. Can't be inferred.
D. Can't be inferred.
E. Can't be inferred as both waves can be reliable since vertical maping is also important.

B seems to be the best answer! Why E?
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Re: Insect-eating bats rely heavily on echolocation, a method of sensory p  [#permalink]

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03 Sep 2019, 08:59
Official Explanation

3. Which of the following can properly be inferred from the passage?

Difficulty Level: 750

Explanation

On the GMAT, the answer to an inference question must be directly supported by evidence from the text. As always, be sure to pay particular attention to the precise words used in the answer choices and how these words relate to the information presented in the passage.

(A) The second paragraph of the passage states that “lower frequency sounds are spread more vertically, while higher frequency sounds emit more horizontally”. Thus, sound waves are emitted in a range of directions rather than just vertically and horizontally.

(B) The second paragraph of the passage relates the importance that the grooves found on noseleaves play in echolocation. No information is given concerning the role that the spikes play. Because we have no information about the spikes, we cannot infer anything about their role during echolocation.

(C) The passage does highlight the importance of echolocation, but it neither contrasts this ability with bats’ sense of sight nor even mentions the sense of sight. Thus, this answer choice is outside the scope of the passage.

(D) The first paragraph of the passage states that bats use high-frequency sound waves “since high-frequency waves do not diffract, or bend, extensively” (lines 11-13). Thus, it can be inferred that low-frequency sound waves diffract more than high-frequency sound waves.

(E) CORRECT. The first paragraph of the passage states that “while using echolocation, these bats emit a series of short, high-frequency sounds from their mouths or nostrils”. Then, the first sentence of the second paragraph indicates that “bats emit slightly different frequencies in differing situations.” Taken together, these statements confirm that bats emit only high frequencies during echolocation. The variations in the sound waves' frequencies are slight, so that even the "lower frequency sounds" are within the range considered high-frequency.

Hope it helps

sha2nk1931 wrote:
In ques # 3. Why the ans is not B.

A. waves are emitted in different directions. Rejected
B.
C. Can't be inferred.
D. Can't be inferred.
E. Can't be inferred as both waves can be reliable since vertical maping is also important.

B seems to be the best answer! Why E?

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Re: Insect-eating bats rely heavily on echolocation, a method of sensory p  [#permalink]

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07 Sep 2019, 00:29
I got question 2 wrong, can someone please explain which conclusion are we trying to weaken and how choice A is the correct answer?
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Re: Insect-eating bats rely heavily on echolocation, a method of sensory p  [#permalink]

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07 Sep 2019, 01:44
Welcome to GMAT Club !

Official Explanation

2. Which of the following, if true, would most weaken the conclusion concerning the purpose of bats’ noseleaves?

Difficulty Level: 750

Explanation

According to the passage, the purpose of the noseleaves is to help bats “perform difficult tasks, such as locating prey while avoiding obstacles.” The noseleaves do so by allowing bats to emit differing frequencies of sound in different directions. These sound waves “bounce off objects and surfaces and then return to the animals’ ears,” providing the bats with vital information about their surroundings. To weaken the conclusion about the purpose of noseleaves, we must demonstrate that they do not necessarily aid bats in accessing this vital information.

(A) CORRECT. For the noseleaves to contribute to the bats’ understanding of their surroundings, the bats must be able to interpret the information provided by the different frequencies of sound. According to this choice, the bats are emitting at various frequencies, but are “receiving” only a small percentage of what they emit. This idea weakens the conclusion that the noseleaves, by allowing bats to emit a greater range of frequencies, contribute to an enhanced awareness of the immediate environment.

(B) The fact that many bats emit sounds through their mouths does not weaken the conclusion concerning the purpose of noseleaves for those bats that do possess this distinctive feature.

(C) Dolphins live in an environment that is completely different from that of bats. Thus, it is not possible to draw definitive conclusions about the noseleaves of bats simply because dolphins lack such a feature.

(D) For several reasons, the fact that some bats rely on sight and smell does not undermine the conclusion about noseleaves. First, we do not know which bats act in this manner or whether these bats even possess noseleaves. Second, “some” is an ambiguous term; it could refer to a few species of bats rather than a large number. Finally, the passage implies that echolocation is most useful while bats are in motion and their prey is also in motion (echolocation allows bats to “snatch insects out of the air”). It is very possible that bats have alternative strategies when their sources of food are stationary.

(E) The limited range of echolocation does not undermine the purpose of the noseleaves. It is very possible that many “difficult” tasks must be accomplished within a short distance from where bats emit their signals.

Hope it helps

ayushi1219 wrote:
I got question 2 wrong, can someone please explain which conclusion are we trying to weaken and how choice A is the correct answer?

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Re: Insect-eating bats rely heavily on echolocation, a method of sensory p   [#permalink] 07 Sep 2019, 01:44
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