Directions: There are four black squares [<] in the passage, indicating where the following sentence could be added.

This definition is widely accepted by biologists and zoologists, but its application isn’t always simple. Where would the sentence fit best?

Mark the square [<] to add the sentence to the passage.

Directions: Read the passage and answer the following question.

SALAMANDERS AND SPECIES NAMES

 When reviewing the current journals of taxonomy, the science of organizing animals into neat little classifications, it is important to remember that names are a human convenience. Nature is not concerned with putting her creations into simple and objective categories. The classifications that we now have are the result of the scientists’ need to put some sort of order into what is a very chaotic situation. And although taxonomists have the best intentions when naming and classifying new or existing species, there are many occasions when naming a species causes quite a bit of confusion.

An excellent example of the problem with naming species is the case of Ensatina, a genus of salamander found in the Central Valley area of California. Central Valley is about 40 miles wide, and although salamanders do not live in the valley itself, they are found in the forests and mountains that ring the valley. At the southern tip of the valley live two distinct types of salamander—one salamander is characterized by its yellow and black spots, whereas the other is light brown in color and has no spots.

(A <) In biology, a species is typically defined as a group of animals that breed only with one another. (B <) Thus, any two animals that can breed belong to the same species, whereas animals that are unable to breed with one another are of a different species. (C <) The two Central Valley salamanders do not interbreed, which would seem to make it pretty clear that the salamanders should be classified as different species. (D <)

 But there is one interesting problem with these salamanders. A number of other salamanders inhabit the ring surrounding Central Valley. Moving north along the eastern side of the valley, the salamanders have fewer and fewer blotches. At the northern end of the valley, the salamanders appear to be a mixture of the two species; these salamanders are mostly brown, but they still have visible blotches.

Now, moving south along the western end of the valley, the salamanders have blotches that are more and more pronounced. Finally, by the time the southern tip of the valley is reached, the salamanders fully resemble the yellow and black spotted species. The salamanders in effect form an almost continuous ring around the outside of the Central Valley, and although the two distinct species at the “ends” of the ring do not interbreed, the salamanders can and do breed with “the intermediates” along the ring So although it is fairly clear that the salamanders at the ends of the ring are distinct species, what of the other salamanders found around the valley?

This situation presents quite a problem in classification. Most taxonomists have decided that the best solution is to put each of the intermediary salamanders into its own subspecies. However, this messy solution results in ten different species names for a salamander that is found only in the Central Valley. One can imagine how such a solution, applied to other species, could result in hundreds of thousands of subspecies for each species.

Further complicating the situation is the new evidence from genetic studies. It appears that the salamanders in Central Valley are all rather closely related, meaning that they all probably evolved from a common ancestor. A likely scenario is that the ancestral salamander species arrived at either the northern or southern tip of the valley and dispersed from there, with the offspring moving farther and farther down the eastern and western sides of the valley. In any case, the genetic evidence indicates a continuous gene flow along the Central Valley.

Directions: Choose the word nearest in meaning from the given options for the word convenience in the passage.

Directions: Read the passage and answer the following question.

SALAMANDERS AND SPECIES NAMES

 When reviewing the current journals of taxonomy, the science of organizing animals into neat little classifications, it is important to remember that names are a human convenience. Nature is not concerned with putting her creations into simple and objective categories. The classifications that we now have are the result of the scientists’ need to put some sort of order into what is a very chaotic situation. And although taxonomists have the best intentions when naming and classifying new or existing species, there are many occasions when naming a species causes quite a bit of confusion.

An excellent example of the problem with naming species is the case of Ensatina, a genus of salamander found in the Central Valley area of California. Central Valley is about 40 miles wide, and although salamanders do not live in the valley itself, they are found in the forests and mountains that ring the valley. At the southern tip of the valley live two distinct types of salamander—one salamander is characterized by its yellow and black spots, whereas the other is light brown in color and has no spots.

(A <) In biology, a species is typically defined as a group of animals that breed only with one another. (B <) Thus, any two animals that can breed belong to the same species, whereas animals that are unable to breed with one another are of a different species. (C <) The two Central Valley salamanders do not interbreed, which would seem to make it pretty clear that the salamanders should be classified as different species. (D <)

 But there is one interesting problem with these salamanders. A number of other salamanders inhabit the ring surrounding Central Valley. Moving north along the eastern side of the valley, the salamanders have fewer and fewer blotches. At the northern end of the valley, the salamanders appear to be a mixture of the two species; these salamanders are mostly brown, but they still have visible blotches.

Now, moving south along the western end of the valley, the salamanders have blotches that are more and more pronounced. Finally, by the time the southern tip of the valley is reached, the salamanders fully resemble the yellow and black spotted species. The salamanders in effect form an almost continuous ring around the outside of the Central Valley, and although the two distinct species at the “ends” of the ring do not interbreed, the salamanders can and do breed with “the intermediates” along the ring So although it is fairly clear that the salamanders at the ends of the ring are distinct species, what of the other salamanders found around the valley?

This situation presents quite a problem in classification. Most taxonomists have decided that the best solution is to put each of the intermediary salamanders into its own subspecies. However, this messy solution results in ten different species names for a salamander that is found only in the Central Valley. One can imagine how such a solution, applied to other species, could result in hundreds of thousands of subspecies for each species.

Further complicating the situation is the new evidence from genetic studies. It appears that the salamanders in Central Valley are all rather closely related, meaning that they all probably evolved from a common ancestor. A likely scenario is that the ancestral salamander species arrived at either the northern or southern tip of the valley and dispersed from there, with the offspring moving farther and farther down the eastern and western sides of the valley. In any case, the genetic evidence indicates a continuous gene flow along the Central Valley.

How can the layout of the passage be described?

Directions: Read the following passage and answer the question.
While historians focus mainly on the macro events that cause perceptible changes, the economists are more concerned with the minute details. It is a well known fact that many a time in history, the act of a single person has been responsible for a paradigm shift in the way the story is told. The economists go into the most exiguous detail possible to reach a conclusion. Also, the history is written by the victor, but economics thrives on various theories put forth by a multitude of experts. It therefore comes as no surprise that, even on an event of the magnitude of the Great Depression, the experts in the two subjects have conflicting views.
While the historians ascribe the meltdown to a host of macro factors like the cataclysmic crash of the stock market, the failure of the banks, and unemployment, the economists are more intent on finding the nuances and the recondite riff surrounding the turn of events. According to them, the rot in the system started much before and the Great Depression was actually a culmination of causative events rather than the starting point itself. They point towards the deflationary actions of the Federal Reserve, including regulating the currency in circulation in accordance to the Gold Standard and increasing the interest rates as some of the principal causes behind the fiasco. Also, the fact that Great Britain went back to pre World War Gold Standard also set in motion a set of protectionist policies that killed off trade between nations and added fuel to the fire. Although government spending, or rather the lack of it, is blamed for the crisis, a casual perusal of government spending in 1930 clearly points out that the governmental spending actually increased year on year in an effort to revive the economy. However, in a case of too little, too late, the actions failed to yield the desired results.
The historians cite bank failures and the reluctance of banks to lend money as a key factor. Blaming the lack of foresight by the financial regulators and the government, the economists contend that the stock market crash so frightened the common citizens that the they stopped spending. The decreased spending triggered off a chain of events that had far reaching repercussions. Businesses struggling to keep their heads above the water laid off employees to cut costs. This in turn, resulted in further reduction in consumer spending.
It is in our best interest if reconciliation between these two fields of study can be effected. It will allow us to sum up the findings with a degree of consensus that appeals not only to the scholars of economics but also to the historians who look for patterns in history.

What according to the passage is the main cause of bickering about the Great Depression between the two fields of study?

Directions: Read the following passage and answer the question.
While historians focus mainly on the macro events that cause perceptible changes, the economists are more concerned with the minute details. It is a well known fact that many a time in history, the act of a single person has been responsible for a paradigm shift in the way the story is told. The economists go into the most exiguous detail possible to reach a conclusion. Also, the history is written by the victor, but economics thrives on various theories put forth by a multitude of experts. It therefore comes as no surprise that, even on an event of the magnitude of the Great Depression, the experts in the two subjects have conflicting views.
While the historians ascribe the meltdown to a host of macro factors like the cataclysmic crash of the stock market, the failure of the banks, and unemployment, the economists are more intent on finding the nuances and the recondite riff surrounding the turn of events. According to them, the rot in the system started much before and the Great Depression was actually a culmination of causative events rather than the starting point itself. They point towards the deflationary actions of the Federal Reserve, including regulating the currency in circulation in accordance to the Gold Standard and increasing the interest rates as some of the principal causes behind the fiasco. Also, the fact that Great Britain went back to pre World War Gold Standard also set in motion a set of protectionist policies that killed off trade between nations and added fuel to the fire. Although government spending, or rather the lack of it, is blamed for the crisis, a casual perusal of government spending in 1930 clearly points out that the governmental spending actually increased year on year in an effort to revive the economy. However, in a case of too little, too late, the actions failed to yield the desired results.
The historians cite bank failures and the reluctance of banks to lend money as a key factor. Blaming the lack of foresight by the financial regulators and the government, the economists contend that the stock market crash so frightened the common citizens that the they stopped spending. The decreased spending triggered off a chain of events that had far reaching repercussions. Businesses struggling to keep their heads above the water laid off employees to cut costs. This in turn, resulted in further reduction in consumer spending.
It is in our best interest if reconciliation between these two fields of study can be effected. It will allow us to sum up the findings with a degree of consensus that appeals not only to the scholars of economics but also to the historians who look for patterns in history.

What is the author trying to convey in the passage?

Directions: Read the following passage and answer the question.
Unlike a long, very long, spiral staircase inside a lighthouse, the top of which, though invisibly lost in the mists of darkness is present, or perhaps a mountain much higher than the highest, but still having a discernable acme, the journey of consciousness does not stop at any level. Like exploring an underwater maze of caves, deep under the sea, in almost pitch darkness, the human soul transcends the boundaries and barriers of time and space. There is no life-line to haul oneself back to safety if lost or paralyzed with fear, the sense of spatial reasoning is in abeyance, the eyes are nearly blind due to the pitch darkness, and yet one must feel one’s way forward by using the truncated senses to the best of one’s ability. The darkness holds unknown fears - real, and those conjured by one’s senses, unseen challenges and pitfalls as well as good and nasty surprises within its bosom and yet the journey must go on because to stop and give up means getting stuck at the same spot for eternity. According to many scientists and philosophers, time and space are the only two anchors that give us a sense of progress, direction and spatial reasoning and if both of these are removed, as they have been suggested by thinkers and visionaries alike to be the props created by humans, then nothing is left. Our world is perhaps the creation of our mind and death erases our mind like a hard drive wiped clean of all data, till the time comes for it to start storing data again on the next plane of consciousness. It is like giving up the familiar comfort of a familiar landing and venturing out in the dark unknown again. Time is relative, we live in different time zones, there is day in one part of the world while another is shrouded by the darkness of the night. The time spent waiting for a lover makes every second seem like an eternity while the same time rushes past when the deadline for some important task approaches.

The passage implies all of the following about the advent of ballad opera in America, except:

Directions: Read the following passage and answer the question.
In the sometimes faulty and incomplete records of the American stage to which writers on musical history have hitherto been forced to repair, 1750 is set down as the natal year for English ballad opera in America. It is thought that it was in that year that “The Beggar’s Opera” found its way to New York, after having, in all probability, been given by the same company of comedians in Philadelphia in the middle of the year preceding. But it is as little likely that these were the first performances of ballad operas on this side of the Atlantic.
Accepting the 1750 date as the earliest of unmistakable records for a performance of “The Beggar's Opera” in New York, the original home of opera here was the Nassau Street Theater--the first of two known by that name. It was a two-storied house, with high gables. Six wax lights were in front of the stage, and from the ceiling dangled a “barrel hoop,” pierced by half a dozen nails on which were spiked as many candles. Illuminating gas did not reach New York till 1823, and “a thousand candles” was put forth as an attractive feature at a concert in the American metropolis as late as 1845.
“The Beggar's Opera” was only twenty years old when the comedians sent to the colonies by William Hallam, under the management of his brother, Lewis, produced it. The first audience-room was only fifty-four or fifty-five feet deep; there were no footlights, the stage being illuminated by four hoops of candles, over which a crown hung from the borders. The orchestra held only fifteen or twenty musicians. Hallam's actors went first to Williamsburg, Virginia, but were persuaded to change their home to New York in the summer of 1753, among other things by the promise that they would find a “very fine ‘Playhouse Building’” here. Nevertheless, when Lewis Hallam came he found the fine playhouse unsatisfactory, and may be said to have inaugurated the habit or custom, or whatever it may be called, followed by so many managers since, of beginning his enterprise by erecting a new theater. The old one in Nassau Street was torn down, and a new one built on its site. It was promised that it should be “very fine, large, and commodious,” and it was built between June and September, 1753; how fine, large, and commodious it was may, therefore, be imagined. A year later, the German Calvinists, wanting a place of worship, bought the theater, and New York was without a playhouse until a new one on Cruger's Wharf was built by David Douglas. This was abandoned in turn, and Mr. Douglas built a second theater, this time in Chapel Street. It cost $1,625, and can scarcely have been very roomy or very ornate either. Such as it was, however, it was the home of the drama in all its forms until about 1765, and was the center around which a storm raged which culminated in a riot that wrecked it.

What is a suitable title for the passage?

Directions: Read the following passage and answer the question.
In the sometimes faulty and incomplete records of the American stage to which writers on musical history have hitherto been forced to repair, 1750 is set down as the natal year for English ballad opera in America. It is thought that it was in that year that “The Beggar’s Opera” found its way to New York, after having, in all probability, been given by the same company of comedians in Philadelphia in the middle of the year preceding. But it is as little likely that these were the first performances of ballad operas on this side of the Atlantic.
Accepting the 1750 date as the earliest of unmistakable records for a performance of “The Beggar's Opera” in New York, the original home of opera here was the Nassau Street Theater--the first of two known by that name. It was a two-storied house, with high gables. Six wax lights were in front of the stage, and from the ceiling dangled a “barrel hoop,” pierced by half a dozen nails on which were spiked as many candles. Illuminating gas did not reach New York till 1823, and “a thousand candles” was put forth as an attractive feature at a concert in the American metropolis as late as 1845.
“The Beggar's Opera” was only twenty years old when the comedians sent to the colonies by William Hallam, under the management of his brother, Lewis, produced it. The first audience-room was only fifty-four or fifty-five feet deep; there were no footlights, the stage being illuminated by four hoops of candles, over which a crown hung from the borders. The orchestra held only fifteen or twenty musicians. Hallam's actors went first to Williamsburg, Virginia, but were persuaded to change their home to New York in the summer of 1753, among other things by the promise that they would find a “very fine ‘Playhouse Building’” here. Nevertheless, when Lewis Hallam came he found the fine playhouse unsatisfactory, and may be said to have inaugurated the habit or custom, or whatever it may be called, followed by so many managers since, of beginning his enterprise by erecting a new theater. The old one in Nassau Street was torn down, and a new one built on its site. It was promised that it should be “very fine, large, and commodious,” and it was built between June and September, 1753; how fine, large, and commodious it was may, therefore, be imagined. A year later, the German Calvinists, wanting a place of worship, bought the theater, and New York was without a playhouse until a new one on Cruger's Wharf was built by David Douglas. This was abandoned in turn, and Mr. Douglas built a second theater, this time in Chapel Street. It cost $1,625, and can scarcely have been very roomy or very ornate either. Such as it was, however, it was the home of the drama in all its forms until about 1765, and was the center around which a storm raged which culminated in a riot that wrecked it.

The experiment described above is ultimately an attempt to

Directions: The passage below is followed by a question. Answer the question on the basis of what is stated or implied in the passage.

In a major step toward helping paralytic victims walk again, Duke University researchers have announced that they had proved monkeys can use their brainpower to control the walking patterns of robots. The investigators implanted Idoya, a rhesus monkey, with electrodes which gathered signals from her brain's motor and sensory cortex cells as she ambled along on a specially built child-size treadmill. The electrodes recorded the cells' responses as the monkey walked on the treadmill at different speeds; simultaneously, sensors on Idoya's legs tracked their patterns of movement. The information was transmitted real time from their lab in Durham, to control the commands of a humanoid robot in Kyoto, Japan.

Through the electrodes in her brain, the researchers discovered that some neurons fire at different phases and frequencies, depending on their role in the process. During the experiment, the robot continued to move for several minutes after Idoya stopped strolling on her treadmill indicating something else also.

The team’s goal is to finally enable real-time direct interfaces between a brain and electronic and mechanical devices that could be used to restore sensory and motor functions lost through injury or disease. The team hopes that one day soon, they will also master sufficient syntax to talk back to the brain, which would enable them, for instance, to build a human prosthetic arm laden with sensors to send tactile feedback into the somatosensory cortex of its user.

The experiment in monkey-to-robotic motion is the latest in a long series of studying the primate brain's ability to stimulate robotic arms through neural signals. In 2000 Nicolelis and his colleagues described how they had reliably translated the raw electrical brain activity of an owl monkey named Belle into signals that successfully directed the actions of robotic arms based both at Duke and at an MIT lab 965 kilometers away in Cambridge. Belle's tiny hand moved a joystick left or right to correspond with a horizontal series of lights on a display panel in a Duke lab; both robot arms followed suit.

The author’s use of the phrase 'indicating something else also' in the 2^nd paragraph implies most likely which of the following?

Directions: The passage below is followed by a question. Answer the question on the basis of what is stated or implied in the passage.

In a major step toward helping paralytic victims walk again, Duke University researchers have announced that they had proved monkeys can use their brainpower to control the walking patterns of robots. The investigators implanted Idoya, a rhesus monkey, with electrodes which gathered signals from her brain's motor and sensory cortex cells as she ambled along on a specially built child-size treadmill. The electrodes recorded the cells' responses as the monkey walked on the treadmill at different speeds; simultaneously, sensors on Idoya's legs tracked their patterns of movement. The information was transmitted real time from their lab in Durham, to control the commands of a humanoid robot in Kyoto, Japan.

Through the electrodes in her brain, the researchers discovered that some neurons fire at different phases and frequencies, depending on their role in the process. During the experiment, the robot continued to move for several minutes after Idoya stopped strolling on her treadmill indicating something else also.

The team’s goal is to finally enable real-time direct interfaces between a brain and electronic and mechanical devices that could be used to restore sensory and motor functions lost through injury or disease. The team hopes that one day soon, they will also master sufficient syntax to talk back to the brain, which would enable them, for instance, to build a human prosthetic arm laden with sensors to send tactile feedback into the somatosensory cortex of its user.

The experiment in monkey-to-robotic motion is the latest in a long series of studying the primate brain's ability to stimulate robotic arms through neural signals. In 2000 Nicolelis and his colleagues described how they had reliably translated the raw electrical brain activity of an owl monkey named Belle into signals that successfully directed the actions of robotic arms based both at Duke and at an MIT lab 965 kilometers away in Cambridge. Belle's tiny hand moved a joystick left or right to correspond with a horizontal series of lights on a display panel in a Duke lab; both robot arms followed suit.

The author ends the passage on a note of

PASSAGE – I
The passage below is followed by a question based on its content. Answer the question on the basis of what is stated or implied in the passage.

Migratory birds often move in linear flight formations called echelons. Typically, we find V and J-type structures, which are the most readily recognized flock echelons, nevertheless other variations to these major patterns can also be found. A true V-shaped echelon is, in reality, less common than a J formation, studies conducted on several species reveal.
Why do the birds fly in formations? Two well-corroborated and complementary explanations are available right now. A major idea is to save energy by capitalizing on the upwash vortex fields generated by the bird wings in the front. The second - to facilitate the job of orientation and communication among the flying birds. These two explanations are not necessarily mutually exclusive, and in fact, both are supported by many studies. The relative importance of each of them, no doubt, changes as various factors, like the season of the year or the reason behind  individual flights, change. During local feeding flights meant to locate food, for instance, careful orientation and collision avoidance are probably much more important than the conservation of energy. However, during long-distance migration, though orientation and communication remain important, but the case for conservation of energy by optimization of its position holds greater importance for each bird in the flock.

Where should the birds position themselves in relation to others to conserve the most energy as they fly in the air? Fluid dynamics and energy wave configuration calculations supply the answer. Analysts, using photography, have determined bird positions and found them to almost always be located to enable the bird to earn some energetic advantage. However, the birds are not always at the expected optimal location, indicating that other factors also come into play.

Researchers have used the knowledge of birds, visual axes, "blind spots" and visual fields to pinpoint the best locations for a bird in a flock to maintain optimal visual positioning. The actual positions are usually having a positive correlation with these predictions but are, again, not always perfect. The positions of birds have been classified and it has been found that some individuals occupy positions to satisfy the energy conservation principle; others enjoy better visual contact placement, while the rest do not apparently respond to either benefit or are in a position so as to gain some advantage from both the benefits available.

The passage could have been most appropriately titled in which of the following ways?

PASSAGE – I
The passage below is followed by a question based on its content. Answer the question on the basis of what is stated or implied in the passage.

Migratory birds often move in linear flight formations called echelons. Typically, we find V and J-type structures, which are the most readily recognized flock echelons, nevertheless other variations to these major patterns can also be found. A true V-shaped echelon is, in reality, less common than a J formation, studies conducted on several species reveal.
Why do the birds fly in formations? Two well-corroborated and complementary explanations are available right now. A major idea is to save energy by capitalizing on the upwash vortex fields generated by the bird wings in the front. The second - to facilitate the job of orientation and communication among the flying birds. These two explanations are not necessarily mutually exclusive, and in fact, both are supported by many studies. The relative importance of each of them, no doubt, changes as various factors, like the season of the year or the reason behind  individual flights, change. During local feeding flights meant to locate food, for instance, careful orientation and collision avoidance are probably much more important than the conservation of energy. However, during long-distance migration, though orientation and communication remain important, but the case for conservation of energy by optimization of its position holds greater importance for each bird in the flock.

Where should the birds position themselves in relation to others to conserve the most energy as they fly in the air? Fluid dynamics and energy wave configuration calculations supply the answer. Analysts, using photography, have determined bird positions and found them to almost always be located to enable the bird to earn some energetic advantage. However, the birds are not always at the expected optimal location, indicating that other factors also come into play.

Researchers have used the knowledge of birds, visual axes, "blind spots" and visual fields to pinpoint the best locations for a bird in a flock to maintain optimal visual positioning. The actual positions are usually having a positive correlation with these predictions but are, again, not always perfect. The positions of birds have been classified and it has been found that some individuals occupy positions to satisfy the energy conservation principle; others enjoy better visual contact placement, while the rest do not apparently respond to either benefit or are in a position so as to gain some advantage from both the benefits available.

Which of the following questions is / are not answered by the above passage?

1. Does energy conservation have the same importance during short and long flights respectively?
2. Do the bird formations always have a leader having higher social status?
3. Does the season of the year play a role in determining whether a particular theory will be able to account for bird behaviour in an echelon or not?

   PASSAGE – I
   The passage below is followed by a question based on its content. Answer the question on the basis of what is stated or implied in the passage.

   Migratory birds often move in linear flight formations called echelons. Typically, we find V and J-type structures, which are the most readily recognized flock echelons, nevertheless other variations to these major patterns can also be found. A true V-shaped echelon is, in reality, less common than a J formation, studies conducted on several species reveal.
   Why do the birds fly in formations? Two well-corroborated and complementary explanations are available right now. A major idea is to save energy by capitalizing on the upwash vortex fields generated by the bird wings in the front. The second - to facilitate the job of orientation and communication among the flying birds. These two explanations are not necessarily mutually exclusive, and in fact, both are supported by many studies. The relative importance of each of them, no doubt, changes as various factors, like the season of the year or the reason behind  individual flights, change. During local feeding flights meant to locate food, for instance, careful orientation and collision avoidance are probably much more important than the conservation of energy. However, during long-distance migration, though orientation and communication remain important, but the case for conservation of energy by optimization of its position holds greater importance for each bird in the flock.

   Where should the birds position themselves in relation to others to conserve the most energy as they fly in the air? Fluid dynamics and energy wave configuration calculations supply the answer. Analysts, using photography, have determined bird positions and found them to almost always be located to enable the bird to earn some energetic advantage. However, the birds are not always at the expected optimal location, indicating that other factors also come into play.

   Researchers have used the knowledge of birds, visual axes, "blind spots" and visual fields to pinpoint the best locations for a bird in a flock to maintain optimal visual positioning. The actual positions are usually having a positive correlation with these predictions but are, again, not always perfect. The positions of birds have been classified and it has been found that some individuals occupy positions to satisfy the energy conservation principle; others enjoy better visual contact placement, while the rest do not apparently respond to either benefit or are in a position so as to gain some advantage from both the benefits available.

   The leaders of these bird formations change with time, but it has not been possible to discover the causes, frequency and characteristics associated with these changes. Observations on a sustained basis of such flocks covering long distances in the air are very difficult. Several intuitive predictions about the choice of the formation leader that immediately come to mind are - age, experience, sex, condition and social status of the leaders, but so far researchers have been unable to overcome the logistic issues to put these hypotheses to test. Birds have been trained to fly in formation with small aircraft by some scientists; possibly their efforts will yield opportunities to test these hypotheses.

Which of the following statements is the writer most likely to agree with?

1. Bird formations vary in accordance with the bird species.
2. There is positive proof for the theories of bird formation and the position of bird within it
3. Energy conservation seems to be the overarching single factor behind bird formations during all flights.

   PASSAGE – I
   The passage below is followed by a question based on its content. Answer the question on the basis of what is stated or implied in the passage.

   Migratory birds often move in linear flight formations called echelons. Typically, we find V and J-type structures, which are the most readily recognized flock echelons, nevertheless other variations to these major patterns can also be found. A true V-shaped echelon is, in reality, less common than a J formation, studies conducted on several species reveal.
   Why do the birds fly in formations? Two well-corroborated and complementary explanations are available right now. A major idea is to save energy by capitalizing on the upwash vortex fields generated by the bird wings in the front. The second - to facilitate the job of orientation and communication among the flying birds. These two explanations are not necessarily mutually exclusive, and in fact, both are supported by many studies. The relative importance of each of them, no doubt, changes as various factors, like the season of the year or the reason behind  individual flights, change. During local feeding flights meant to locate food, for instance, careful orientation and collision avoidance are probably much more important than the conservation of energy. However, during long-distance migration, though orientation and communication remain important, but the case for conservation of energy by optimization of its position holds greater importance for each bird in the flock.

   Where should the birds position themselves in relation to others to conserve the most energy as they fly in the air? Fluid dynamics and energy wave configuration calculations supply the answer. Analysts, using photography, have determined bird positions and found them to almost always be located to enable the bird to earn some energetic advantage. However, the birds are not always at the expected optimal location, indicating that other factors also come into play.

   Researchers have used the knowledge of birds, visual axes, "blind spots" and visual fields to pinpoint the best locations for a bird in a flock to maintain optimal visual positioning. The actual positions are usually having a positive correlation with these predictions but are, again, not always perfect. The positions of birds have been classified and it has been found that some individuals occupy positions to satisfy the energy conservation principle; others enjoy better visual contact placement, while the rest do not apparently respond to either benefit or are in a position so as to gain some advantage from both the benefits available.

   The leaders of these bird formations change with time, but it has not been possible to discover the causes, frequency and characteristics associated with these changes. Observations on a sustained basis of such flocks covering long distances in the air are very difficult. Several intuitive predictions about the choice of the formation leader that immediately come to mind are - age, experience, sex, condition and social status of the leaders, but so far researchers have been unable to overcome the logistic issues to put these hypotheses to test. Birds have been trained to fly in formation with small aircraft by some scientists; possibly their efforts will yield opportunities to test these hypotheses.

The passage is structured like which of the following?

PASSAGE – I
The passage below is followed by a question based on its content. Answer the question on the basis of what is stated or implied in the passage.

Migratory birds often move in linear flight formations called echelons. Typically, we find V and J-type structures, which are the most readily recognized flock echelons, nevertheless other variations to these major patterns can also be found. A true V-shaped echelon is, in reality, less common than a J formation, studies conducted on several species reveal.
Why do the birds fly in formations? Two well-corroborated and complementary explanations are available right now. A major idea is to save energy by capitalizing on the upwash vortex fields generated by the bird wings in the front. The second - to facilitate the job of orientation and communication among the flying birds. These two explanations are not necessarily mutually exclusive, and in fact, both are supported by many studies. The relative importance of each of them, no doubt, changes as various factors, like the season of the year or the reason behind  individual flights, change. During local feeding flights meant to locate food, for instance, careful orientation and collision avoidance are probably much more important than the conservation of energy. However, during long-distance migration, though orientation and communication remain important, but the case for conservation of energy by optimization of its position holds greater importance for each bird in the flock.

Where should the birds position themselves in relation to others to conserve the most energy as they fly in the air? Fluid dynamics and energy wave configuration calculations supply the answer. Analysts, using photography, have determined bird positions and found them to almost always be located to enable the bird to earn some energetic advantage. However, the birds are not always at the expected optimal location, indicating that other factors also come into play.

Researchers have used the knowledge of birds, visual axes, "blind spots" and visual fields to pinpoint the best locations for a bird in a flock to maintain optimal visual positioning. The actual positions are usually having a positive correlation with these predictions but are, again, not always perfect. The positions of birds have been classified and it has been found that some individuals occupy positions to satisfy the energy conservation principle; others enjoy better visual contact placement, while the rest do not apparently respond to either benefit or are in a position so as to gain some advantage from both the benefits available.

Directions: For each blank select one entry from the corresponding column of choices. Fill all the blanks in the way that best completes the sentence. A black hole is a body which is (i)__ because its gravitational pull is so strong that even light cannot escape from its __(ii)_____ Blank (i) Blank (ii) dark vicinity imperceptible gravity invisible proximity