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Practice Question Question No.: RC 102 ~ 106 Page: 352
Australian researchers have discovered electroreceptors (sensory organs designed to respond to electrical fields) clustered at the tip of the spiny anteater’s snout. The researchers made this discovery by exposing small areas of the snout to extremely weak electrical fields and recording the transmission of resulting nervous activity to the brain. While it is true that tactile receptors, another kind of sensory organ on the anteater’s snout, can also respond to electrical stimuli, such receptors do so only in response to electrical field strengths about 1,000 times greater than those known to excite electroreceptors.
Having discovered the electroreceptors, researchers are now investigating how anteaters utilize such a sophisticated sensory system. In one behavioral experiment, researchers successfully trained an anteater to distinguish between two troughs of water, one with a weak electrical field and the other with none. Such evidence is consistent with researchers’ hypothesis that anteaters use electroreceptors to detect electrical signals given off by prey; however, researchers as yet have been unable to detect electrical signals emanating from termite mounds, where the favorite food of anteaters live. Still, researchers have observed anteaters breaking into a nest of ants at an oblique angle and quickly locating nesting chambers. This ability quickly to locate unseen prey suggests, according to the researchers, that the anteaters were using their electroreceptors to locate the nesting chambers.
1. According to the passage, which of the following is a characteristic that distinguishes electroreceptors from tactile receptors?
(A) The manner in which electroreceptors respond to electrical stimuli (B) The tendency of electroreceptors to be found in clusters (C) The unusual locations in which electroreceptors are found in most species. (D) The amount of electrical stimulation required to excite electroreceptors (E) The amount of nervous activity transmitted to the brain by electroreceptors when they are excited
2. Which of the following can be inferred about the experiment described in the first paragraph?
(A) Researchers had difficulty verifying the existence of electroreceptors in the anteater because electroreceptors respond to such a narrow range of electrical field strengths. (B) Researchers found that the level of nervous activity in the anteater’s brain increased dramatically as the strength of the electrical stimulus was increased. (C) Researchers found that some areas of the anteater’s snout were not sensitive to a weak electrical stimulus. (D) Researchers found that the anteater’s tactile receptors were more easily excited by a strong electrical stimulus than were the electroreceptors. (E) Researchers tested small areas of the anteater’s snout in order to ensure that only electroreceptors were responding to the stimulus.
3. The author of the passage most probably discusses the function of tactile receptors (lines 7-11) [While it is true that tactile receptors, another kind of sensory organ on the anteater’s snout, can also respond to electrical stimuli, such receptors do so only in response to electrical field strengths about 1,000 times greater than those known to excite electroreceptors.] in order to
(A) eliminate an alternative explanation of anteaters’ response to electrical stimuli (B) highlight a type of sensory organ that has a function identical to that of electroreceptors (C) point out a serious complication in the research on electroreceptors in anteaters. (D) suggest that tactile receptors assist electroreceptors in the detection of electrical signals. (E) introduce a factor that was not addressed in the research on electroreceptors in anteaters.
4. Which of the following can be inferred about anteaters from the behavioral experiment mentioned in the second paragraph?
(A) They are unable to distinguish between stimuli detected by their electroreceptors and stimuli detected by their tactile receptors. (B) They are unable to distinguish between the electrical signals emanating from termite mounds and those emanating from ant nests. (C) They can be trained to recognize consistently the presence of a particular stimulus. (D) They react more readily to strong than to weak stimuli. (E) They are more efficient at detecting stimuli in a controlled environment than in a natural environment.
5. The passage suggests that the researchers mentioned in the second paragraph who observed anteaters break into a nest of ants would most likely agree with which of the following statements?
(A) The event they observed provides conclusive evidence that anteaters use their electroreceptors to locate unseen prey. (B) The event they observed was atypical and may not reflect the usual hunting practices of anteaters. (C) It is likely that the anteaters located the ants’ nesting chambers without the assistance of electroreceptors. (D) Anteaters possess a very simple sensory system for use in locating prey. (E) The speed with which the anteaters located their prey is greater than what might be expected on the basis of chance alone.
6. Which of the following, if true, would most strengthen the hypothesis mentioned in lines 17-19 [Such evidence is consistent with researchers’ hypothesis that anteaters use electroreceptors to detect electrical signals given off by prey]?
(A) Researchers are able to train anteaters to break into an underground chamber that is emitting a strong electrical signal. (B) Researchers are able to detect a weak electrical signal emanating from the nesting chamber of an ant colony. (C) Anteaters are observed taking increasingly longer amounts of time to locate the nesting chambers of ants. (D) Anteaters are observed using various angles to break into nests of ants. (E) Anteaters are observed using the same angle used with nests of ants to break into the nests of other types of prey.
Source : Second mammal with a nose for electricity (New Scientist - 25 Mar 1989)
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Australian researchers have discovered electroreceptors (sensory organs designed to respond to electrical fields) clustered at the tip of the spiny anteater's snout. The researchers made this discovery by exposing small areas of the snout to extremely weak electrical fields and recording the transmission of resulting nervous activity to the brain. While it is true that tactile receptors, another kind of sensory organ on the anteater's snout, can also respond to electrical stimuli, such receptors do so only in response to electrical field strengths about 1,000 times greater than those known to excite electroreceptors.
Having discovered the electroreceptors, researchers are now investigating how anteaters utilize such a sophisticated sensory system. In one behavioral experiment, researchers successfully trained an anteater to distinguish between two troughs of water, one with a weak electrical field and the other with none. Such evidence is consistent with researchers' hypothesis that anteaters use electroreceptors to detect electrical signals given off by prey; however, researchers as yet have been unable to detect electrical signals emanating from termite mounds, where the favorite food of anteaters live. Still, researchers have observed anteaters breaking into a nest of ants at an oblique angle and quickly locating nesting chambers. This ability to quickly locate unseen prey suggests, according to the researchers, that the anteaters were using their electroreceptors to locate the nesting chambers.
101. According to the passage, which of the following is a characteristic that distinguishes electro receptors from tactile receptors? (A) The manner in which electroreceptors respond to electrical stimuli (B) The tendency of electroreceptors to be found in clusters (C) The unusual locations in which electroreceptors are found in most species. (D) The amount of electrical stimulation required to excite electroreceptors (E) The amount of nervous activity transmitted to the brain by electroreceptors when they are excited
102. Which of the following can be inferred about the experiment described in the first paragraph? (A) Researchers had difficulty verifying the existence of electroreceptors in the anteater because electroreceptors respond to such a narrow range of electrical field strengths. (B) Researchers found that the level of nervous activity in the anteater’s brain increased dramatically as the strength of the electrical stimulus was increased. (C) Researchers found that some areas of the anteater’s snout were not sensitive to a weak electrical stimulus. (D) Researchers found that the anteater’s tactile receptors were more easily excited by a strong electrical stimulus than were the electro receptors.. (E) Researchers tested small areas of the anteater’s snout in order to ensure that only electroreceptors were responding to the stimulus.
103. The author of the passage most probably discusses the function of tactile receptors (lines 7-11) in order to (A) eliminate and alternative explanation of anteaters’ response to electrical stimuli (B) highlight a type of sensory organ that has a function identical to that of electroreceptors (C) point out a serious complication in the research on electroreceptors in anteaters. (D) suggest that tactile receptors assist electroreceptors in the detection of electrical signals. (E) introduce a factor that was not addressed in the research on electroreceptors in anteaters.
104. Which of the following can be inferred about anteaters from the behavioral experiment mentioned in the second paragraph? (A) They are unable to distinguish between stimuli detected by their electroreceptors and stimuli detected by their tactile receptors. (B) They are unable to distinguish between the electrical signals emanating from termite mounds and those emanating from ant nests. (C) They can be trained to recognize consistently the presence of a particular stimulus. (D) They react more readily to strong than to weak stimuli. (E) They are more efficient at detecting stimuli in a controlled environment than in a natural environment.
105. The passage suggests that the researchers mentioned in the second paragraph who observed anteaters break into a nest of ants would most likely agree with which of the following statements?(A) The event they observed provides conclusive evidence that anteaters use their electroreceptors to locate unseen prey. (B) The event they observed was a typical and may not reflect the usual hunting practices of anteaters. (C) It is likely that the anteaters located the ants’ nesting chambers without the assistance of electroreceptors. (D) Anteaters possess a very simple sensory system for use in locating prey. (E) The speed with which the anteaters located their prey is greater than what might be expected on the basis of chance alone.
106. Which of the following, if true, would most strengthen the hypothesis mentioned in lines 17-19? (A) Researchers are able to train anteaters to break into an underground chamber that is emitting a strong electrical signal. (B) Researchers are able to detect a weak electrical signal emanating from the nesting chamber of an ant colony. (C) Anteaters are observed taking increasingly longer amounts of time to locate the nesting chambers of ants. (D) Anteaters are observed using various angles to break into nests of ants. (E) Anteaters are observed using the same angle used with nests of ants to break into the nests of other types of prey.
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15 Sep 2012, 06:30
Q2. Which of the following can be inferred about the experiment described in the first paragraph? (A) Researchers had difficulty verifying the existence of electroreceptors in the anteater because electroreceptors respond to such a narrow range of electrical field strengths. (B) Researchers found that the level of nervous activity in the anteater’s brain increased dramatically as the strength of the electrical stimulus was increased. (C) Researchers found that some areas of the anteater’s snout were not sensitive to a weak electrical stimulus. (D) Researchers found that the anteater’s tactile receptors were more easily excited by a strong electrical stimulus than were the electroreceptors. (E) Researchers tested small areas of the anteaters snout in order to ensure that only electroreceptors were responding to the stimulus Answer - C
Q3 The passage suggests that the researchers mentioned in the second paragraph who observed anteaters break into a nest of ants would most likely agree with:- (A) The event that observed provides conclusive evidence that anteaters use their electroreceptors to locate unseen preys (B) The event they observed was atypical and may not reflect the usual hunting practices of the anteaters (C) It is likely that the anteaters located the ants' nesting chambers without the assistance of electroreceptors. (D) Anteaters possess a very simple sensory system for use in locating prey. (E) The speed with which the anteaters located their prey is greater than what might be expected on the basis of chance alone. Answer - E
Q4 Which of the following if true would most strengthen the hypothesis mentioned in the second para? (A) Researchers are unable to train anteaters to break into an underground chamber that is emitting a strong electrical signal (B) Researchers are able to detect a weak electrical signal emanating from the nesting chamber of an ant colony (C) Anteaters are observed taking increasingly longer amounts of time to locate the nesting chamber of ants (D) Anteaters are observed using various angles to break into the nests of ants. (E) Anteaters are observed using the same angle used with nests of ants to break into the nests of other types of prey. Answer - B
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01 Oct 2012, 00:38
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Q3: Last line of the passage clearly suggests that the researchers are agreeing that anteaters located the chambers quickly because of electroreceptors. Hence E
This ability quickly to locate unseen prey suggests, according to the researchers, that the anteaters were using their electroreceptors to locate the nesting chambers.
Q4. The hypotheseis that needs to be strengthened is "anteaters use electroreceptors to detect electrical signals given off by prey"
researchers experimented anteaters in a weak electrical field and concluded that anteaters can detect weak electrical signals and hypothesized their theory that anteaters use electroreceptors to locate their prey. But according to the passage, researchers are still not sure of any electrical signals emanating from termite mounds. This points out a gap in their hyposthesis. option B fillls the gap.
let me know if any further questions.
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02 Oct 2012, 20:57
anshunadir wrote:
Q3: Last line of the passage clearly suggests that the researchers are agreeing that anteaters located the chambers quickly because of electroreceptors. Hence E
This ability quickly to locate unseen prey suggests, according to the researchers, that the anteaters were using their electroreceptors to locate the nesting chambers.
Q4. The hypotheseis that needs to be strengthened is "anteaters use electroreceptors to detect electrical signals given off by prey"
researchers experimented anteaters in a weak electrical field and concluded that anteaters can detect weak electrical signals and hypothesized their theory that anteaters use electroreceptors to locate their prey. But according to the passage, researchers are still not sure of any electrical signals emanating from termite mounds. This points out a gap in their hyposthesis. option B fillls the gap.
let me know if any further questions.
Ya... What you said about 3 is absolutely correct. Then how come the answer is E? It should be A. Your reasoning suggests A more than E. Am I missing something? 4 is fine.
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03 Oct 2012, 23:12
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Quote:
Ya... What you said about 3 is absolutely correct. Then how come the answer is E? It should be A. Your reasoning suggests A more than E. Am I missing something? 4 is fine.
Having discovered the electroreceptors, researchers are now investigating how anteaters utilize such a sophisticated sensory system. In one behavioral experiment, researchers successfully trained an anteater to distinguish between two troughs of water, one with a weak electrical field and the other with none. Such evidence is consistent with researchers’ hypothesis that anteaters use electroreceptors to detect electrical signals given off by prey; however, researchers as yet have been unable to detect electrical signals emanating from termite mounds, where the favorite food of anteaters live. Still, researchers have observed anteaters breaking into a nest of ants at an oblique angle and quickly locating nesting chambers. This ability quickly to locate unseen prey suggests, according to the researchers, that the anteaters were using their electroreceptors to locate the nesting chambers.
I have divided the second para into three parts(using different colors) Experiment in Red text already says that anteaters use electroreceptors to locate their prey. So if the question was about this experiment, option A would have been a better option. But the question talks about the experiment in blue text which only talks about how quickly anteaters were able to locate the prey colonies because of elecroreceptors. Also, the last line of red text says anteaters use electroreceptors to detect electrical signals and the text in green says that researchers have been unable to detect any electrical signals emanating from prey colonies. This again holds against A which says conclusive evidence.
let me know if any further questions.
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Australian researchers have discovered electroreceptors (sensory organs designed to respond to electrical fields) clustered at the tip of the spiny anteater’s snout. The researchers made this discovery by exposing small areas of (5) the snout to extremely weak electrical fields and recording the transmission of resulting nervous activity to the brain. While it is true that tactile receptors, another kind of sensory organ on the anteater’s snout, can also respond to electrical stimuli, such receptors do so only in response to ( 10) electrical field strengths about 1,000 times greater than those known to excite electroreceptors.
Having discovered the electroreceptors, researchers are now investigating how anteaters utilize such a sophisticated sensory system. In one behavioral experiment, researchers (15) successfully trained an anteater to distinguish between two troughs of water, one with a weak electrical field and the other with none. Such evidence is consistent with researchers’ hypothesis that anteaters use electroreceptors to detect electrical signals given off by prey; however, ( 20) researchers as yet have been unable to detect electrical signals emanating from termite mounds, where the favorite food of anteaters live. Still, researchers have observed anteaters breaking into a nest of ants at an oblique angle and quickly locating nesting chambers. This ability quickly (25)to locate unseen prey suggests, according to the researchers, that the anteaters were using their electroreceptors to locate the nesting chambers.
Which of the following, if true, would most strengthen the hypothesis mentioned in lines 17-19?
(A) Researchers are able to train anteaters to break into an underground chamber that is emitting a strong electrical signal. (B) Researchers are able to detect a weak electrical signal emanating from the nesting chamber of an ant colony. (C) Anteaters are observed taking increasingly longer amounts of time to locate the nesting chambers of ants. (D) Anteaters are observed using various angles to break into nests of ants. (E) Anteaters are observed using the same angle used with nests of ants to break into the nests of other types of prey.
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08 Mar 2013, 12:36
The OA given is
(B) Researchers are able to detect a weak electrical signal emanating from the nesting chamber of an ant colony.
But how can Researchers' (not anteaters) ability to detect a weak electrical signal emanating from the nesting chamber of an ant colony corroborate the Researchers' hypothesis about anteaters?
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08 Mar 2013, 13:20
StrivingTurtle wrote:
The OA given is
(B) Researchers are able to detect a weak electrical signal emanating from the nesting chamber of an ant colony.
But how can Researchers' (not anteaters) ability to detect a weak electrical signal emanating from the nesting chamber of an ant colony corroborate the Researchers' hypothesis about anteaters?
Hi Turtle,
This RC question is a disguised CR strengthening question.
The conclusion is that anteaters use electrical signal to detect their prey. In the premises it is given that the anteater can distinguish water trough of weak electrical signal. It is also given that the anteater is able to quickly find the nesting chamber of ants.
(B) Researchers are able to detect a weak electrical signal emanating from the nesting chamber of an ant colony.
If researchers are able to detect a weak signal then it means that the anteater is using the weak electrical signal to detect its prey. We can say this because it is given in the passage that the anteater can detect a weak electrical signal in a water trough. As compared to other choices (B) gives us a strengthener to the researchers' hypothesis
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08 Mar 2013, 13:47
Hi Vercules,
Thanks for the very prompt reply.
See my question is.. How can researcher's ability to detect the signals corroborate their hypothesis?
Agreed that anteater can detect a weak electrical signal in a water trough... but how did you conclude that an anteater is indeed using the weak electrical signal to detect its prey. ... It could be the case that researchers are using some equipment to detect this signal.
Why cannot choice D be the strengthener? The fact that [i]Anteaters are observed using various angles to break into nests of ants.[/i] suggests that there are reasons other than visual stimuli that prompt the anteaters to do so?
You can of course poke holes in this choice too.. saying that electrical signals need not be the reason for anteaters to break into ant nests at various angles. But given the following facts i feel this to be a stronger option as compared to the OA
Facts: >>researchers have observed anteaters breaking into a nest of ants at an oblique angle and quickly locating nesting chambers >>according to the researchers, the anteaters were using their electroreceptors to locate the nesting chambers.
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10 Mar 2013, 10:08
hypothesis that anteaters use electroreceptors to detect electrical signals given off by prey; however, ( 20) researchers as yet have been unable to detect electrical signals emanating from termite mound
from this text we can reach B , D is irrelevant to discussion and even may weaken because if they use various angles then how can we say that they are using electroreceptors ? E is better because single angle means some thing being detected but still we need additional assumption that angle depends on the electric field. In strengthen and weaken we do get such nicely crafted options which seem relevant but need additional assumption, these are always wrong. the hypothesis must be strengthened with the answer choice only and no additional information added.
B tells they have detected a weak signal from ant's nest , that they were unable to detect from termite mound. thats mentioned in passage . and that strengthens
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17 Mar 2013, 04:23
Australian researchers have discovered electroreceptors (sensory organs designed to respond to electrical fields) clustered at the tip of the spiny anteater’s snout. The researchers made this discovery by exposing small areas of the snout to extremely weak electrical fields and recording the transmission of resulting nervous activity to the brain. While it is true that tactile receptors, another kind of sensory organ on the anteater’s snout, can also respond to electrical stimuli, such receptors do so only in response to electrical field strengths about 1,000 times greater than those known to excite electroreceptors.
Having discovered the electroreceptors, researchers are now investigating how anteaters utilize such a sophisticated sensory system. In one behavioral experiment, researchers successfully trained an anteater to distinguish between two troughs of water, one with a weak electrical field and the other with none. Such evidence is consistent with researchers’ hypothesis that anteaters use electroreceptors to detect electrical signals given off by prey; however, researchers as yet have been unable to detect electrical signals emanating from termite mounds, where the favorite food of anteaters live. Still, researchers have observed anteaters breaking into a nest of ants at an oblique angle and quickly locating nesting chambers. This ability quickly to locate unseen prey suggests, according to the researchers, that the anteaters were using their electroreceptors to locate the nesting chambers.
1. According to the passage, which of the following is a characteristic that distinguishes electroreceptors from tactile receptors? (A) The manner in which electroreceptors respond to electrical stimuli (B) The tendency of electroreceptors to be found in clusters (C) The unusual locations in which electroreceptors are found in most species (D) The amount of electrical stimulation required to excite electroreceptors (E) The amount of nervous activity transmitted to the brain by electroreceptors when they are excited
2. Which of the following can be inferred about the experiment described in the first paragraph? (A) Researchers had difficulty verifying the existence of electroreceptors in the anteater because electroreceptors respond to such a narrow range of electrical field strengths. (B) Researchers found that the level of nervous activity in the anteater’s brain increased dramatically as the strength of the electrical stimulus was increased. (C) Researchers found that some areas of the anteater’s snout were not sensitive to a weak electrical stimulus. (D) Researchers found that the anteater’s tactile receptors were more easily excited by a strong electrical stimulus than were the electroreceptors. (E) Researchers tested small areas of the anteater’s snout in order to ensure that only electroreceptors were responding to the stimulus.
3. The author of the passage most probably discusses the function of tactile receptors (lines 7-11) in order to (A) eliminate and alternative explanation of anteaters’ response to electrical stimuli (B) highlight a type of sensory organ that has a function identical to that of electroreceptors (C) point out a serious complication in the research on electroreceptors in anteaters (D) suggest that tactile receptors assist electroreceptors in the detection of electrical signals (E) introduce a factor that was not addressed in the research on electroreceptors in anteaters
4. Which of the following can be inferred about anteaters from the behavioral experiment mentioned in the second paragraph? (A) They are unable to distinguish between stimuli detected by their electroreceptors and stimuli detected by their tactile receptors. (B) They are unable to distinguish between the electrical signals emanating from termite mounds and those emanating from ant nests. (C) They can be trained to recognize consistently the presence of a particular stimulus. (D) They react more readily to strong than to weak stimuli. (E) They are more efficient at detecting stimuli in a controlled environment than in a natural environment.
5. The passage suggests that the researchers mentioned in the second paragraph who observed anteaters break into a nest of ants would most likely agree with which of the following statements? (A) The event they observed provides conclusive evidence that anteaters use their electroreceptors to locate unseen prey. (B) The event they observed was atypical and may not reflect the usual hunting practices of anteaters. (C) It is likely that the anteaters located the ants’ nesting chambers without the assistance of electroreceptors. (D) Anteaters possess a very simple sensory system for use in locating prey. (E) The speed with which the anteaters located their prey is greater than what might be expected on the basis of chance alone.
6. Which of the following, if true, would most strengthen the hypothesis mentioned in lines 17-19? (A) Researchers are able to train anteaters to break into an underground chamber that is emitting a strong electrical signal. (B) Researchers are able to detect a weak electrical signal emanating from the nesting chamber of an ant colony. (C) Anteaters are observed taking increasingly longer amounts of time to locate the nesting chambers of ants. (D) Anteaters are observed using various angles to break into nests of ants. (E) Anteaters are observed using the same angle used with nests of ants to break into the nests of other types of prey.
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