DIRECTIONS for questions 1 to 5: Read the given passage and answer the questions.
Why do the vital organs of the body slow down on aging? Why do older people experience sleep disorders? A new study holds the molecular machinery of the "master clock" in the brain responsible for such malfunctions during old age. The study conducted by researchers at the University of Virginia and reported in the journal 'Proceedings' of the National Academy of Sciences, compares the working of the vital organs to a wall full of clocks with a large dominant clock controlling the synchronization of the peripheral clocks. The big clock continues to keep time, but as it ages, its connecting signal to the "smaller docks weakens. Some of the smaller clocks eventually become desynchronized and some stop running. This weakening of the signal, rather than a problem with the central timekeeper itself, apparently is the cause of alterations in the biological timing system in aging mammals — possibly including humans, according to the researchers.
This may explain why older people experience sleep disorders the signal from the master clock in the brain has weakened, even as it keeps on ticking. This weakened output causes some of the peripheral clocks in other organs to eventually stop oscillating or to fall out of proper sync, causing sleep disruption and malaise, the report says. Lack of sleep can affect more than a person's level of alertness. In the long term, it can disrupt the body's metabolism; affect eating cycles, lead to declining cognitive abilities and possibly, a shortened lifespan. Sleep disorders are also associated with Alzheimer's disease.
Gene D. Block, professor of biology and one of the study's lead researchers, was quoted in the report as saying, "Our new finding demonstrates that the molecular machinery of the master clock continues to function normally. Taken together with our earlier studies, this suggests that there may be an age-related failure of the conversion of the clock's molecular rhythm into the electrical or humeral signals that the brain uses for communication. These weakened central signals may fail to keep some peripheral clocks appropriately synchronized or, in some cases, even rhythmic." The scientists studied tissues from the brain and other organs of older mice and measured the activity of a gene that is a part of the biological clock. They found that the central dock in the brain, the suprachiasmatic nucleus, maintained proper periodicity and synchronization. Clocks in some peripheral organs, such as the liver and kidney of older animals, were either improperly synchronized or had lost rhythm entirely. "This new knowledge could eventually lead to new therapies for age-related desynchronization," Block said. "Arrhythmic or improperly synchronized tissues of old animals could possibly be stimulated by a treatment to oscillate normally."
Which of these factors is held responsible for the slowing down of the vital organs in old age as laid down in the passage?
Molecular machinery of the master clock and the peripheral clocks in the brain
Weakening of the signals from the master clock in the brain
Master clock in the brain
Sleep disorders
Answer : Option A.
Choice A is stated in the lines, “Taken together with our earlier studies, this suggests that there may be an age-related failure of the conversion of the clock's molecular rhythm into the electrical or humeral signals that the brain uses for communication. These weakened central signals may fail to keep some peripheral clocks appropriately synchronized or, in some cases, even rhythmic."
Which of the following sentences is incorrect, according to the passage?
The connecting signals of the big clock fail as it ages.
The brain uses humeral signals, which are converted from the clock's molecular rhythm.
Alterations in the biological timing system are restricted to lower mammals only.
None of these
Answer : Option C.
As mentioned in the passage, “This weakening of the signal, rather than a problem with the central timekeeper itself, apparently is the cause of alterations in the biological timing system in aging mammals — possibly including humans, according to the researchers.”
What was the breakthrough achieved, as a result of the scientist's effort?
The discovery of the fact that the clocks in some peripheral organs were either improperly synchronized or had lost their rhythm completely
The observation that the brain uses humeral signals for communication
The knowledge that the oscillation is necessary to maintain a person's level of alertness
None of these
Answer : Option A.
Refer to the lines, “The scientists studied tissues from the brain and other organs of older mice and measured the activity of a gene that is a part of the biological clock. They found that the central dock in the brain, the suprachiasmatic nucleus, maintained proper periodicity and synchronization. Clocks in some peripheral organs, such as the liver and kidney of older animals, were either improperly synchronized or had lost rhythm entirely.”
Which of the following sentences is true, in the context of the passage?
The brain of a guinea pig was used for the tissue experimentation
The big clock is directly synchronized to smaller clocks through tissues
Declining cognitive abilities may be traced to sleeplessness
None of these
Answer : Option C.
Choice 3 is clearly mentioned in the lines, “Lack of sleep can affect more than a person's level of alertness. In the long term, it can disrupt the body's metabolism, affect eating cycles, lead to declining cognitive abilities and possibly, a shortened lifespan.”
Which of the following sentences is incorrect, according to the passage?
There is a similarity in the functioning of the brain and the vital organs of the human body with that of a wall full of clocks and the big clock synchronizing them
The study of tissues from the brain and other organs of mice helped scientists discover that even though the suprachiasmatic nucleus maintained time properly, the clocks in the peripheral organs were either out of sync or had lost rhythm entirely.
The molecular machinery of the brain is responsible for the entire malfunctioning occurring at older ages
None of these
Answer : Option C.
The passage suggests that it is the weakening of signals from the master clock to the peripheral clocks that results in malfunctioning.
DIRECTIONS for questions 6 to 7: In each of these questions a statement is followed by two courses of action numbered I and II. Assume everything in the statement to be true. Decide which of the suggested courses of action logically follow(s) for pursuing.
Statement: The Librarian finds some cases in which the pages from certain books issued from the library are torn.
Courses of Action :
I. The Librarian should keep a record of books issued to each student, and if the pages are found torn, strict measures should be taken against the child who had been issued that book.
II. Some funds should be collected from the children collectively to renovate the library.
if only course of action I follows
if neither course of action I nor II follows
if only course of action II follows
if both courses of action I and II follow
Answer : Option A.
1. I is appropriate, Finding out students responsible for damage is important for the school – not only for charging them for the damages, but also for disallowing them to use the library if the action repeats. II is not a relevant course of action because it does not arise out of the cause specified in the statement.
Statement: The availability of imported fruits has increased in the indigenous market and so the demand for indigenous fruits has decreased.
Courses of Action :
I. To help the indigenous producers of fruits, the Government should impose high import duty on these fruits, even if these are not of good quality.
II. The fruit vendors should stop selling imported fruits so that the demand for indigenous fruits would be increased.
if only course of action I follows
if neither course of action I nor II follows
if only course of action II follows
if both courses of action I and II follow
Answer : Option B.
B. It seems that indigenous fruit producers can be helped by I, as people will buy cheaper produce if the quality is the same. However, this does not mean that the demand of indigenous fruit will go up as people could still prefer the imported fruit if it is of a far better quality. II is difficult to implement, as voluntarily why should a fruit seller harm his own business. Thus neither course of action follows.
DIRECTIONS for questions 8 to 9: In each of the following questions, out of the given alternatives,' choose the one which best expresses the meaning of the given word.
ALUMNUS
Ex-student
Saint
Delicate
Calm
Answer : Option A.
Alumnus means older student or ex student.
FINERY
Decoration
Torture
Extract
Imprison
Answer : Option A.
Finery means - expensive or ostentatious clothes or decoration.
DIRECTIONS for question 10: Pick out the most effective word from the given words to fill in the blanks to make the sentence meaningfully complete.
Two buses collided _____________ each other on the road.
between
Into
Onto
With
Answer : Option D.
As preposition 'with is used with collided. Also change option A from into to 'On' as 'Into' causes an ambiguity.
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