Problems

Directions for Questions 1-10: Read the passage and answer the questions that follow on the basis of the information provided in the passage.

Passage 1

For a period of more than two centuries paleontologists have been intrigued by the fossilized remains of pterosaurs, the first flying vertebrates. The issues, which puzzle them, are how these heavy creatures, having a wingspan of about 8-12 meters managed the various problems associated with powered flight and whether these creatures were reptiles or birds.

Perhaps the least controversial assertion about the pterosaurs is that they were reptiles. Their skulls, pelvises, and hind feet are reptilian. The anatomy of their wings suggests that they did not evolve into the class of birds. In pterosaurs a greatly elongated fourth finger of each forelimb supported a winglike membrane. The other fingers were short and reptilian, with sharp claws. In birds the second finger is the principal strut of the wing, which consists primarily of feathers. If the pterosaurs walked on all fours, the three short fingers may have been employed for grasping. When a pterosaurs walked or remained stationary, the fourth finger, and with it the wing, could only urn upward in an extended inverted V- shape along each side of the animal’s body.

In resemblance they were extremely similar to both birds and bats, with regard to their overall body structure and proportion. This is hardly surprising as the design of any flying vertebrate is subject to aerodynamic constraints. Both the pterosaurs and the birds have hollow bones, a feature that represents a savings in weight. There is a difference, which is that the bones of the birds are more massively reinforced by internal struts.

Although scales typically cover reptiles, the pterosaurs probably had hairy coats. T.H. Huxley reasoned that flying vertebrates must have been warm-blooded because flying implies a high rate of metabolism, which in turn implies a high internal temperature. Huxley speculated that a coat of hair would insulate against loss of body heat and might streamline the body to reduce drag in flight. The recent discovery of a pterosaur specimen covered in long, dense, and relatively thick hair like fossil material was the first clear evidence that his reasoning was correct.

Some paleontologists are of the opinion that the pterosaurs jumped from s dropped from trees or perhaps rose into the light winds from the crests of waves in order to become airborne. Each theory has its associated difficulties. The first makes a wrong assumption that the pterosaurs hind feet resembled a bat’s and could serve as hooks by which the animal could hang in preparation for flight. The second hypothesis seems unlikely because large pterosaurs could not have landed in trees without damaging their wings. The third calls for high aces to channel updrafts. The pterosaurs would have been unable to control their flight once airborne as the wind from which such waves arose would have been too strong.

  1. As seen in the above passage scientists generally agree that:
    1. the pterosaurs could fly over large distances because of their large wingspan.
    2. a close evolutionary relationship can be seen between the pterosaurs and bats, when the structure of their skeletons is studied.
    3. the study of the fossilized remains of the pterosaurs reveals how they solved the problem associated with powered flight
    4. the pterosaurs were reptiles
    5. Pterosaurs walked on all fours.

 

2. As inferred from the passage, the skeleton of a pterosaur is distinguishable from that of a bird by the

  1. length of its wingspan
  2. hollow spaces in its bones
  3. anatomic origin of its wing strut
  4. evidence of the hooklike projections on its hind feet
  5. location of the shoulder joint joining the wing to its body.

 

3. From the viewpoint of T.H.Huxley, as given in the passage, which of the following statements is he most likely to agree with?

  1. An animal can master complex behaviors irrespective of the size of it’s brain.
  2. Environmental capabilities and physical capabilities often influence the appearance of an animal.
  3. Usually animals in a particular family group do not change their appearance dramatically over a period of time
  4. The origin of flight in vertebrates was an accidental development rather than the outcome of specialization or adaption
  5. The pterosaurs should be classified as birds, not reptiles.

 

4. The organization of the last paragraph of the passage can best be described as:

  1. New data is introduced in order to support a traditional point of view
  2. Three explanations are put forth and each of them is disputed by means of specific information
  3. An outline of three hypotheses are given and evidence supporting each of them is given
  4. Description of three recent discoveries is presented, and their implications for future study are projected
  5. The material in the earlier paragraphs is summarized and certain conclusions are from it.

 

5. According to the passage, some scientists believe that pterosaurs

  1. Lived near large bodies of water
  2. Had sharp teeth for tearing food
  3. Were attacked and eaten by larger reptiles
  4. Had longer tails than many birds
  5. Consumed twice their weight daily to maintain their body temperature.

 

6. The view that, the pterosaurs rose into light winds from the crest of the waves to become airborne, is viewed by the author as

  1. revolutionary
  2. unlikely
  3. unassailable
  4. probable
  5. outdated.

Passage 2

The Food and Drug Administration has formulated certain severe restrictions regarding the use of antibiotics, which are used to promote the health and growth of meat animals. Though the different types of medicines mixed with the fodder of the animals kills many microorganisms, it also encourages the appearance of bacterial strains, which are resistant to anti-infective drugs.

It has already been observed that penicillin and the tetracyclines are not as effective therapeutically as they once used to be. This resistance to drugs is chiefly caused due to tiny circlets of genes, called plasmids, which are transferable between different species of bacteria. These plasmids are also one of the two kinds of vehicles on which molecular biologists depend on while performing gene transplant experiments. Existing guidelines also forbid the use of plasmids, which bear genes for resistance to antibiotics, in the laboratories. Though congressional debate goes on as to whether these restrictions need to be toughened with reference to scientists in their laboratories, almost no congressional attention is being paid to an ill advised agricultural practice, which produces deleterious effects.

7. In the present passage, the author’s primary concern is with:

      1. The discovery of methods, which eliminate harmful microorganisms without generating drug-resistant bacteria.
      2. Attempting an explanation of the reasons for congressional inaction about the regulation of gene transplant experiments.
      3. Portraying a problematic agricultural practice and its serious genetic consequences
      4. The verification of the therapeutic ineffectiveness of anti-infective drugs
      5. Evaluation of the recently proposed restrictions, which are intended to promote the growth of meat animals.

 

8. As inferred from the above passage, the mutual transfer of plasmids between different bacteria can result in which of the following?

      1. Microorganisms, which have an in-built resistance to drugs
      2. Therapeutically useful circlets of genes
      3. Penicillin like anti-infective drugs
      4. Viruses used by molecular biologists
      5. Carriers for performing gene transplant experiments.

 

9. According to the above passage the author believes that those who favor the stiffening of restrictions on gene transplant research should logically also.

      1. Approve and aid experiments with any plasmids except those, which bear genes for antibiotic resistance.
      2. Inquire regarding the addition of anti-infective drugs to livestock feeds
      3. Oppose the using of penicillin and tetracyclines in order to kill microorganisms
      4. Agree to the development of meatier live-stock through the use of antibiotics
      5. Approve of congressional debate and discussion regarding science and health issues.

 

10. The attitude the author has with reference to the development of bacterial strains that render antibiotic drugs in effective can best be described as

    1. indifferent
    2. perplexed
    3. pretentious
    4. insincere
    5. apprehensive

Answers

  1. Answer: 4
  2. Answer: 3
  3. Answer: 2
  4. Answer: 2
  5. Answer: 1
  6. Answer: 2
  7. Answer: 3 – The Food and Drug Administration has formulated certain severe restrictions regarding the use of antibiotics, which are used to promote the health and growth of meat animals.
  1. Answer: 1 – Existing guidelines also forbid the use of plasmids, which bear genes for resistance to antibiotics, in the laboratories.
  1. Answer: 2 – Almost no congressional attention is being paid to an ill advised agricultural practice, which produces deleterious effects.
  1. Answer: E – The author is very anxious as stated in the last line. Almost no congressional attention is being paid to an ill advised agricultural practice, which produces deleterious effects.