1. The passage is primarily concerned with assessing
(A) the effects of a devastating bacterial infection in Atlantic coast bottlenose dolphins -
too specific discussed only in 3rd para(B) the process by which illnesses in Atlantic coast bottlenose dolphins were correctly diagnosed -
incorrect and too specific. The first diagnosis process was a hypothesis.(C) the weaknesses in the research methodology used to explore the dolphin die-off -
tempting but too specific. Discussed only in the last paragraph.(D) possible alternative explanations for the massive dolphin die-off - Correct.
1st and 2nd para introduces the die-offs and one possible explanation. 3rd para elaborates this explanation and 4th para proposes an alternative explanation.
(E) relative effects of various marine pollutants on dolphin mortality -
too specific.2. Which one of the following is mentioned in the passage as evidence for the explanation of the dolphin die-off offered in the final paragraph?
(A) the release of stored brevetoxins from the dolphins’ blubber reserves -
blubber reserves are discussed in 3rd para(B) the date on which offshore dumping was known to have occurred nearby -
date is not discussed.(C) the presence of dumping sites for PCBs in the area -
not discussed(D) the synthetic pollutants that were present in the fish eaten by the dolphins -
Discussed in 3rd para(E) the effects of PCBs on liver function in dolphins -
Correct Inference -
"PCB poisoning is known to impair functioning
of the immune system and liver and to cause skin
lesions; all of these problems were observed in the
diseased animals.3. Which one of the following is most analogous to the approach taken by the author of the passage with regard to the research described in the third paragraph?
Here's what I think to infer :
Researchers - "The combined impact made the dolphins vulnerable to opportunistic bacterial infection, the ultimate cause of death."
Author - "For several reasons, however, this explanation is not entirely plausible. "
Author - "Although brevetoxin may have been a contributing factor, the event that actually precipitated the die-off was a sharp increase in the dolphins’ exposure to synthetic pollutants"
(A) A physics teacher accepts the data from a student’s experiment but questions the student’s conclusions. -
Correct. Inline with the statements made above. Think of Author as Teacher and Researchers as Students.(B) An astronomer provides additional observations to support another astronomer’s theory. -
NO theories/hypothesis are supported in the passage with additional premise.(C) A cook revises a traditional recipe by substituting modern ingredients for those used in the original. -
If we consider cook as author here, then the author actually provides an alternative and not a revision of original hypothesis.(D) A doctor prescribes medication for a patient whose illness was misdiagnosed by another doctor. -
If we consider a doctor as an author then we have to consider another doctor as another author whereas comparisons are between explanations of author and researchers.(E) A microbiologist sets out to replicate the experiment that yielded a classic theory of cell structure. -
Irrelevant. Neither author nor researchers replicate anything 4. Which one of the following most accurately describes the organization of the last paragraph?
(A) One explanation is criticized and a different explanation is proposed. -
Correct. Author criticizes the researchers explanation as "not entirely plausible" and proposes different explanation of "increase in pollutants"(B) An argument is advanced and then refuted by means of an opposing argument. -
Researcher's explanation is neither advanced nor refuted directly.(C) Objections against a hypothesis are advanced, the hypothesis is explained more fully, and then the objections are rejected. -
Absolutely not. Even if it seems as an objection from author, that objection at the end is supported by an alternative explanation and NOT rejected.(D) New evidence in favor of a theory is described, and then the theory is reaffirmed. -
Opposite. No new evidence in favor of researchers.(E) Discrepancies between two explanations are noted, and a third explanation is proposed. -
There are only two explanations in the passage and NOT three.5. It can be inferred from the passage that the author would most probably agree with which one of the following statements about brevetoxin?
(A) It may have been responsible for the dolphins’ skin lesions but could not have contributed to the bacterial infection. -
PCB is known to cause skin lesions. According to author "Although brevetoxin may have been a contributing factor, ..."(B) It forms more easily when both P. brevis and synthetic pollutants are present in the environment simultaneously. -
Incorrect. Easy formation is not discussed.(C) It damages liver function and immune system responses in bottlenose dolphins but may not have triggered this particular dolphin die-off. -
Incorrect. Same as A, PCB is know to cause these disorders and according to author "Although brevetoxin may have been a contributing factor, ..."(D) It is unlikely to be among the factors that contributed to the dolphin die-off. -
Again incorrect. According to author "Although brevetoxin may have been a contributing factor, ..."(E) It is unlikely to have caused the die-off because it was not present in the dolphins’ environment when the die-off began. -
CorrectInference - " Although brevetoxin may have been a contributing factor, the event that actually precipitated the die-off was a sharp increase in the dolphins’ exposure to synthetic pollutants."6. The explanation for the dolphin die-off given by the research team most strongly supports which one of the following?
(A) The biological mechanism by which brevetoxin affects dolphins is probably different from that by which it affects other marine animals. -
difference in effects on other marine animals are not discussed.(B) When P. brevis blooms in an area where it does not usually exist, it is more toxic than it is in its usual habitat. -
Not true. It is toxic where it blooms. It was equally toxic along atlantic coast as it was in its usual habitat.(C) Opportunistic bacterial infection is usually associated with brevetoxin poisoning in bottlenose dolphins. -
Opportunistic bacterial infection is associated with both Brevetoxin and PCB combined.(D) The dolphins’ emaciated state was probably a symptom of PCB poisoning rather than of brevetoxin poisoning -
It was, according to researchers, both combined. (E) When a dolphin metabolizes its blubber, the PCBs released may be more dangerous to the dolphin than they were when stored in the blubber. -
Correct.
Inference - "dolphins indicated
that they were metabolizing their blubber reserves, thereby reducing their buoyancy and insulation (and adding to overall stress) as well as releasing stores of previously accumulated synthetic pollutants, such as PCBs, which further exacerbated their condition." 7. The author refers to dolphins in the Gulf of Mexico in the last paragraph in order to
Inference - "bottlenose dolphins and P. brevis red tides are both common in the Gulf of Mexico, yet no dolphin die-off of a similar magnitude has been noted there." (A) refute the assertion that dolphins tend not to inhabit areas where P. brevis is common -
Not true. They can co-exist.(B) compare the effects of synthetic pollutants on these dolphins and on Atlantic coast dolphins -
Synthetic pollutants are not considered.(C) cast doubt on the belief that P. brevis contributes substantially to dolphin die-offs -
Correct. Inline with inference.(D) illustrate the fact that dolphins in relatively pollution-free waters are healthier than dolphins in polluted waters. -
Out of scope.(E) provide evidence for the argument that P. brevis was probably responsible for the dolphins’ deaths -
Opposite. Evidence to refute that P. brevis may was the cause of die-offs.8. Which one of the following factors is explicitly cited as contributing to the dolphins’ deaths in both theories discussed in the passage?
Researchers - "Tests for synthetic pollutants revealed that polychlorinated biphenyls (PCBs) were present in almost all animals tested.
Author - "Although brevetoxin may have been a contributing factor, the event that actually precipitated the die-off was a sharp increase in the dolphins’ exposure to synthetic pollutants."(A) the dolphins diet -
Only discussed by researchers(B) the presence of P. brevis in the Gulf of Mexico -
Only discussed by author.(C) the wide variety of toxins released by the red tide bloom of October 1987 -
Brevetoxin may have contributed and NOT a variety of toxins(D) the presence of synthetic pollutants in the dolphins’ bodies -
Correct. Inline with inference.(E) the bacterial infection caused by a generalized failure of the dolphins’ immune systems -
Only discussed by researchers _________________
Posting my own explanation on forum helps me to review my mistakes :)
16 Nov 2020, 03:34
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