Although some progress has been made in the last two decades on the treatment of Alzheimer’s disease, the causes of the disease are still largely unknown. A recent study conducted by the National Institute of Aging (NIA) appears to have found new evidence concerning the origins of Alzheimer’s. Scientists who carried out the study at NIA focused on the correlation between a patient’s genetic history, which scientists usually agree is the basis of Alzheimer’s, and the onset of Alzheimer’s. The evidence cited by the NIA team includes the identification of the apolipoprotein E (APOE) as the specific gene that may be responsible for the onset of Alzheimer’s. The APOE gene can be sub-divided into many different forms, but the NIA research team has identified one specific form of APOE, the APOE ?4 gene, as a very likely cause of Alzheimer’s. The presence of APOE ?4 is known to make an individual particularly vulnerable to both cognitive and vascular dysfunction, which are among the chief symptoms of Alzheimer’s.
However, a review of the study and its results by the Center for Disease Control and Prevention (CDC) maintains that the evidence discovered by the NIA may not necessarily indicate that the APOE ?4 gene is responsible for Alzheimer’s. CDC experts have pointed out that APOE ?4 is known to cause conditions such as cardiac disease and diabetes in patients who have no genetic history of Alzheimer’s and are not considered at risk for the disease. Further, the CDC review team has observed that APOE ?4 has been found in individuals who show no symptoms of Alzheimer’s. In response to the CDC’s review, the NIA team has pointed out that the APOE ?4 gene may be dormant in some individuals, suggesting that the absence of Alzheimer’s in individuals who have the APOE ?4 gene cannot be used as evidence to rule out this gene as the cause of Alzheimer’s disease.
1. The primary purpose of the passage is to
A. present information that goes against a particular finding about a disease
B. propose further investigation to come to a conclusive result in a dispute about the cause of a disease
C. resolve the controversy about the treatment of a disease
D. evaluate a dispute about whether genetic factors could be the basis of a disease
E. present the findings of a new study and debate over the same
The author presents both sides of an argument about whether the gene APOE ?4 could be the cause of Alzheimer’s disease. Notice that the author does not support or refute either of the contrasting positions or arrive at a conclusion about which of the two positions could be correct.
A. Incorrect: Partial scope
This statement only captures part of the passage in which the author indicates that CDC does not agree with the NIA’s findings.
B. Incorrect: Out of scope
The author does not make any proposal in the passage.
C. Incorrect: Irrelevant
First, the controversy is not about the treatment of AD, but about the cause of AD. Second, as observed in our pre-thinking, the author does not arrive at any conclusion or resolve the controversy described in the passage.
D. Incorrect: Irrelevant
First, the author does not present any evaluation. Second, the dispute is about the cause of AD and not about whether genetic history could be the basis of AD.
E. Correct
This choice matches the result of our passage analysis.
2. The author makes which of the following statements about the relevance of genetic history as the basis of Alzheimer’s disease?
A. The NIA is the first to claim it.
B. It is disputed by the CDC’s expert review team.
C. It is not generally disputed by scientists.
D. It has been challenged by the researchers at NIA.
E. It makes the NIA’s finding unlikely to be correct.
This is a Detail question. To prethink the answer, we must first read the question carefully and identify which part of the passage the answer is located in.
The question asks us to identify what the author states about the identification of genetic history as the basis of AD. It is stated in Paragraph 1 Sentence 3 that “scientists usually agree” that genetic history is the basis of AD. Note that the correct answer could restate this information in slightly different words.
A. Incorrect: Out of scope
We are not told who first established the link between genetic history and the disease.
B. Incorrect: Inconsistent
The dispute or argument is regarding a particular cause of the disease and not whether genetic history has any role to play in developing Alzheimer’s.
C. Correct
It is stated in Paragraph 1 Sentence 3 that “scientists usually agree” that genetic history is the basis of AD.
D. Incorrect: Inconsistent
This statement is not disputed by anyone.
E. Incorrect: Out of Scope
The NIA’s finding that a specific gene is the probable cause of AD is not weakened by the accepted belief that genetic history is the basis of AD.
3. Which of the following claims does the NIA support by providing the information that the APOE ?4 gene may be dormant in some individuals?
A. The presence of the APOE ?4 gene and the absence of Alzheimer’s in the same individual does not weaken the claim that the APOE ?4 likely causes Alzheimer’s.
B. Individuals in whom the APOE ?4 gene is dormant are at high risk for Alzheimer’s disease.
C. The fact that individuals with dormant APOE ?4 gene show no sign of Alzheimer’s does not indicate that genetic history is not the basis of the disease.
D. The absence of Alzheimer’s in individuals with the APOE ?4 gene makes it unlikely that APOE ?4 is the cause of Alzheimer’s.
E. The dormancy of the APOE ?4 gene is an indication that this gene may cause cardiac disease and diabetes even when it doesn’t cause Alzheimer’s.
This is a Detail question. The correct answer will closely follow what is directly stated in the passage.
This information is stated in the last sentence of the passage. It is part of the NIA’s response to the CDC’s position. The sentence tells us that the APOE ?4 gene may be inactive in certain people, indicating that the absence of AD in people who have the APOE ?4 gene does not weaken the possibility that this gene causes AD.
A. Correct
This choice correctly restates the information provided in the last sentence of the passage.
B. Incorrect: Out of Scope
There is no mention of the probability of developing AD in people in whom the APOE ?4 gene is dormant.
C. Incorrect: Out of Context
The relevance of genetic history as a basis for AD is never debated in the entire passage. The debate is regarding whether APOE ?4 gene is a likely cause of AD and the information given regarding the dormancy of the gene is also in support of the link between this particular gene and the disease. This choice picks up relevant terminologies from the passage but mixes up their contexts.
D. Incorrect: Opposite
This choice states the opposite of what the author states in the last sentence of the passage. According to the passage, as per the NIA, the absence of AD in people who have the APOE ?4 gene information “cannot be used as evidence to rule out” the claim that the APOE ?4 gene is the cause of AD.
E. Incorrect: Out of Context
The point regarding the APOE ?4 gene’s causing cardiac disease and diabetes is brought out in a different context by the CDC and not the NIA.
4. Which of the following best describes the function of the first sentence of the second paragraph?
A. It provides evidence to support the claim that the APOE ?4 gene is the likely cause of Alzheimer’s disease.
B. It offers new evidence that contradicts the previously accepted belief that a person’s genetic history is the basis of Alzheimer’s disease.
C. It states a position that does not favor the findings of a study conducted at the National Institute of Aging.
D. It provides an opinion that, if true, could lead to more effective methods of treatment for conditions such as cardiac disease and diabetes.
E. It suggests that methods of data collection used in the study conducted by the National Institute of Aging were flawed.
The first sentence of the second paragraph gives us the CDC’s position on the NIA’s claim that the APOE ?4 gene is the probable cause of AD. The CDC review team believes that the NIA’s position may not be viable.
A. Incorrect: Inconsistent
First, the statement of interest in the passage does not support the NIA’s claim: it opposes it. Second, it does not provide evidence: it provides an opinion.
B. Incorrect: Inconsistent
The statement of interest in the passage does not pertain to the person’s genetic history as the basis of AD. Also, it does not provide any evidence.
C. Correct
This choice correctly identifies the function of the statement of interest.
D. Incorrect: Out of Scope
The statement of interest (and in fact the entire passage) does not mention anything about the treatment for these conditions.
E. Incorrect: Out of Scope
The statement of interest does not pertain to the methods used in the NIA study. It questions the findings of the study but not the methods used in the study.
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Updated on: 15 Oct 2019, 04:14
25%
(medium)
31%
(02:36) wrong 
