English: Reading Comprehension Set 15


Directions: Read the following passage and answer the questions that follows.

EXPERIMENTS that go according to plan can be useful. But the biggest scientific advances often emerge from those that do not. Such is the case with a study just reported in the Proceedings of the National Academy of Sciences. When they began it, Hector DeLuca of the
University of Wisconsin, Madison, and his colleagues had been intending to examine the effects of ultraviolet (UV) light on mice suffering from a rodent version of multiple sclerosis (MS). By the project’s end, however, they had in their hands two substances which
may prove valuable drugs against the illness. Multiple sclerosis is an autoimmune disease. This means it is caused by a victim’s immune system turning on and destroying parts of his own body. In the case of MS the targets of these attacks, which may continue for years, are the fatty sheaths that insulate nerve cells and thus help nervous impulses to propagate. People suffering from MS are often weakened, and sometimes physically disabled by it, and may also become blind. What drives the immune system to behave in this way remains mysterious, but in the 1970s researchers uncovered a promising clue when they noticed that MS is rarer near the equator than it is at high latitudes. The first hypothesis proposed to explain this observation was that vitamin D (a substance created by sunlight’s action on
precursor molecules in the skin) might be helping to prevent MS. That made sense, since those living in the tropics receive more sunlight than do those in temperate zones. Sadly, follow-up experiments failed to support the notion. Those experiments did, though, lead Dr DeLuca to discover that the preventive effect is associated with a particular sort of sunlight—UV with a wavelength of between 300 and 315 nanometres (billionths of a metre). His latest experiment was intended to dig deeper into this observation, by using this type of light to irradiate mice that had been injected with chemicals known to cause the rodent equivalent of MS. In a preliminary study he and his colleagues therefore shaved the backs of 12 of these mice and exposed them to UV of the appropriate wavelength every day for a month. To be useful, an experiment like this needs controls with which its results can be compared. Dr DeLuca devised three of these. In one, he applied one of six types of sunscreen to a dozen other shaved mice before exposing them to the ultraviolet rays. To another dozen he applied the sunscreen but not the ultraviolet. And a final 12, though also shaved, were neither exposed to UV nor slathered with sunscreen. He then monitored all four groups for signs of murine multiple sclerosis, such as loss of tail tone, unsteady gait and limb paralysis. When the experiment began, he and his colleagues expected that the disease would progress more slowly in the experimental group than in the control groups, and that its rate of progress in all three control groups would be the same, since any effect of exposure to ultraviolet would be negated by the sunscreen. But that was not what happened. Instead, three of the six types of sunscreen served to suppress the disease’s progression by themselves—that is, even in animals not exposed to UV. Indeed, one of them, Coppertone, was as effective at doing so as ultraviolet light alone.

In light of this Dr DeLuca and his colleagues carried out further experiments, which confirmed the initial findings. They also studied the ingredients lists of the three protective sunscreens and tested each of the compounds therein, one at a time, on other batches of
mice. This revealed that two of these compounds, homosalate and octisalate, were particularly effective at keeping the rodent version of multiple sclerosis in check. Why these particular substances suppress MS remains to be discovered. Dr DeLuca suspects that it has
to do with their ability to inhibit production of cyclooxygenase, an enzyme commonly found in the lesions characteristic of multiple sclerosis. But regardless of the mechanism, if homosalate and octisalate, or other molecules similar to them, can suppress the progression of the disease in people as effectively as they do in rodents it will be a signal example both of the role of serendipity in science and of the crucial importance of doing proper controls.

  1. Why Multiple Sclerosis is a rare phenomenon near Equator
    A) Equatorial region recieve more sunlight
    B) Vitamin D is sufficiently avaible at Equator
    C) Both A & D
    D) UV sunrays of wavelength 300~315nm available at equator
    E) Both B & D
    View Answer
      Option D
  2. Compounds help in keeping rodent version of Sclerosis at check are:
    A) homosalate
    B) octisalate
    C) pesto salate
    D) Both A & B
    E) None of these.
    View Answer
      Option D
  3. What is the most appropriate synonym of “ slathered”:
    A) couple
    B) sprinkle
    C) boatload
    D) dab
    E) spread
    View Answer
      Option E
  4. Which  of the following is incorrect according to the passage?
    A) Hector DeLuca belongs to University of Wisconsin
    B) Sclerosis is low at Temprate regions and high at tropicals.
    C) Multiple sclerosis is an autoimmune disease
    D) vitamin D is a substance created by sunlight’s action
    E) All are false.
    View Answer
      Option B
  5. How many dozens of mice is being used for the main experiment?
    A) Two
    B) Three
    C) Four
    D) Five
    E) None of these.
    View Answer
      Option C
  6. What according to the passage is true abooout Dr. DeLuca
    A) She devised five  experiments in controlled manner.
    B) Discovered that UV with a wavelength of between 300 and 315 is effective on mice
    C) She was born in Madison
    D) All are true.
    E) None of these.
    View Answer
      Option B
  7. What are the causes of Multiple Sclerosis?
    i. turning on immune system
    ii. propagation of nerve impulse
    iii. destroying self body parts
    A) Only i
    B) All of these
    C) Both i & iii
    D) All except iii
    E) Not mentioned in the passage
    View Answer
      Option C
  8. The phrase “turning on” means:
    A) arouse
    B) enchant
    C) thrill
    D) get srated
    E) None of these.
    View Answer
      Option D
  9. What is the most possible antonym of “propagate”:
    A) beget
    B) transmit
    C) rear
    D) procliam
    E) conceal
    View Answer
      Option E
  10. What is the suitable title for the passage?
    A) Know Yourself
    B) Know Scleoris
    C) Unexpected protection
    D) MS: a propagating dilemma
    E) None of these.
    View Answer
      Option C

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8 Thoughts to “English: Reading Comprehension Set 15”

  1. Ravi Upadhyay


  2. Jeetesh Chandra


  3. swati

    9/9 but it took me 12 minutes…anyways thank you team AZ

  4. naruto

    8/10 thanks, team az kindly increase the level

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