Although it is now possible to bring most high blood pressure under

Question

New Project RC Butler 2019  -  Practice 2 RC Passages Everyday   
Passage # 461, Date: 19-Nov-2019
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Although it is now possible to bring most high blood pressure under control, the causes of essential hypertension remain elusive. Understanding how hypertension begins is at least partly a problem of understanding when in life it begins, and this may be very early—perhaps within the first few months of life. Since the beginning of the century, physicians have been aware that hypertension may run in families, but before the 1970s, studies of the familial aggregation of blood pressure treated only populations 15 years of age or older. Few studies were attempted in younger persons because of a prevailing notion that blood pressures in this age group were difficult to measure and unreliable and because essential hypertension was widely regarded as a disease of adults.

In 1971, a study of 700 children, ages 2 to 14, used a special blood pressure recorder which minimizes observer error and allows for standardization of blood pressure readings. Before then, it had been well established that the blood pressure of adults aggregates familially, that is, the similarities between the blood pressure of an individual and his siblings are generally too great to be explained by chance. The 1971 study showed that familial clustering was measurable in children as well, suggesting that factors responsible for essential hypertension are acquired in childhood. Additional epidemiological studies demonstrated a clear tendency for the children to retain the same blood pressure patterns, relative to their peers, four years later.  Thus, a child with blood pressure higher or lower than the norm would tend to remain higher or lower with increasing age.

Meanwhile, other investigators uncovered a complex of physiologic roles— including blood pressure—for a vasoactive system called the kallikreinkininsystem. Kallikreins are enzymes in the kidney and blood plasma which act on precursors called kininogens to produce vasoactive peptides called kinins. Several different kinins are produced, at least three of which are (powerful blood vessel dilators. Apparently, the kallikrein-kinin system normally tends to offset the elevations in arterial pressure that result from the secretion of salt-conserving hormones such as aldosterone on the one hand and from activation of the sympathetic nervous system (which tends to constrict blood vessels) on the other hand.

It is also known that urinary kallikrein excretion is abnormally low in subjects with essential hypertension. Levels of urinary kallikrein in children are inversely related to the diastolic blood pressures of both children and their mothers. Children with the lowest kallikrein levels are found in the families with the highest blood pressures.  In addition, black children tend to show somewhat lower urinary kallikrein levels than white children, and blacks are more likely to have high blood pressure.  There is a great deal to be learned about the biochemistry and physiologic roles of the kallikrein-kinin system. But there is the possibility that essential hypertension will prove to have biochemical precursors.    1 
 B 
 1. The author is primarily concerned with

(A) questioning the assumption behind certain experiments involving children under the age of 15
(B) describing the new scientific findings about high blood pressure and suggesting some implications
(C) describing two different methods for studying the causes of high blood pressure
(D) revealing a discrepancy between the findings of epidemiological studies and laboratory studies on essential hypertension
(E) arguing that high blood pressure may be influenced by familial factors

2 
 D 
 2. Which of the following is mentioned as a factor that initially discouraged the study of hypertension in children?

(A) An expectation that high blood pressure in children was untreatable
(B) Repeated unsuccessful attempts to treat hypertension in adults
(C) The belief that blood pressure in adults aggregates familially
(D) The belief that it was difficult or impossible to measure accurately blood pressures in children
(E) Ignorance of important differences in the physical constitution of ethnic subgroups

3 
 C 
 3. The argument in the passage leads most naturally to which of the following conclusions?

(A) A low output of urinary kallikrein is a likely cause of high blood pressure in children.
(B) The kallikrein-kinin system plays an important role in the regulation of blood pressure.
(C) Essential hypertension may have biochemical precursors that may be useful predictors in children.
(D) The failure of the body to produce sufficient amounts of kinins is the cause of essential hypertension.
(E) It is now possible to predict high blood pressure by using familial aggregations and urinary kallikrein measurement.

4 
 A 
 4. The author refers to the somewhat lower urinary kallikrein levels in black children ( Text In Red ) in order to

(A) support the thesis that kallikrein levels are inversely related to blood pressure
(B) highlight the special health problems involved in treating populations with high concentrations of black children
(C) offer a causal explanation for the difference in urinary kallikrein levels between black and white children
(D) suggest that further study needs to be done on the problem of high blood pressure among black adults
(E) prove that hypertension can be treated if those persons likely to have high blood pressure can be found

5 
 B 
 5. The author states that the kallikreinkinin system may affect blood pressure by

(A) directly opposing the tendency of the sympathetic nervous system to constrict blood vessels
(B) producing kinins, which tend to dilate blood vessels
(C) suppressing the production of hormones such as aldosterone
(D) controlling the levels of kallikrein in the urine
(E) compensating for cross-subgroup differentials

6 
 C 
 6. The evidence that a child with blood pressure higher or lower than the norm would tend to retain the same blood pressure pattern with increasing age ( Text In Blue ) is introduced by the author in order to

(A) suggest that essential hypertension may have biochemical causes
(B) show that high blood pressure can be detected in children under the age of 15
(C) provide evidence that factors affecting blood pressure are already present in children
(D) propose that increased screening of children for high blood pressure should be undertaken
(E) refute arguments that blood pressure in children cannot be measured reliably

7 
 C 
 7. The author’s argument is presented primarily by

(A) contrasting two methods of doing scientific research
(B) providing experimental evidence against a conclusion
(C) presenting new scientific findings for a conclusion
(D) analyzing a new theory and showing its defects
(E) criticizing scientific research on blood pressure done before 1971

Source:  Master GMAT 
Difficulty Level:   650

saishivapriya · Answer

Can someone post official explanations? Especially for Q3, 6

Sajjad1994 · Answer

Official Explanation

3. The argument in the passage leads most naturally to which of the following conclusions?

Difficulty Level:   700

Explanation

This question asks us to make a further application of the arguments given in the passage, and the greatest danger may be the temptation to overstate the case. This is the difficulty with answer  (E).

The author’s remarks are qualified in the closing sentences. It may be  “possible,”  but it is never asserted that it is now possible to do this.  (D)  also overstates the case. The author states that these chemical deficiencies are associated with high blood pressure, not that such deficiencies cause high blood pressure. And to the extent that one wants to argue that such deficiencies contribute to high blood pressure (based on paragraph three), that is not sufficient to support the causal statement expressed in  (D).

As for  (A) , the author notes that the low output of urinary kallikrein is associated with high blood pressure, that is, it may be another symptom of whatever physiological disorder causes high blood pressure, but that means it is an effect of the underlying cause and not the cause itself.

Finally, (B)  can be eliminated because it is not a further conclusion of the passage. To the extent that  (B)  reiterates what is stated already—and note that  (B)  states the kallikrein-kinin system is important in determining blood pressure, not that the system causes high blood pressure—it is not appropriate as a further statement based on arguments presented.

(C)  is, however, a natural extension of the argument. Remember, the author begins by noting that it is important to determine when high blood pressure begins, and then suggests that it may begin as early as infancy.

The correct answer is (C).

6. The evidence that a child with blood pressure higher or lower than the norm would tend to retain the same blood pressure pattern with increasing age (Text In Blue) is introduced by the author in order to

Difficulty Level:   650

Explanation

This is a logical detail question: Why does the author introduce this information? In the second paragraph the author is describing new research done on children, which suggests that the factors related to high blood pressure are already detectable in children.

(A)  is incorrect since the author has not yet begun to discuss the biochemical research, only epidemiological surveys.

(B)  is incorrect since it is not a correct response to the question. The author does state that such research is actually possible, but does not cite the results of the study in order to prove the study was possible. Rather, the author cites the results to prove the further conclusion outlined in  (C) .

(D)  is incorrect because it is not a response to the question. To be sure, one might use the results of the study cited to support the recommendation articulated in (D), but that is not the author’s motivation for introducing it in argument. As for  (E) , this fails for the same reason that  (B)  fails.

The correct answer is (C).

Hope it helps

fefwfw · Answer

Pls post for 7th ques.. As opt B also possible, as Blacks and white are described as an experimental evidence

Sajjad1994 · Answer

Official Explanation

7. The author’s argument is presented primarily by

Difficulty Level:   600

Explanation

This is a logical structure question. The argument is developed primarily by describing findings and supporting a conclusion.

As for  (A) , though two types of research, epidemiological studies, and clinical studies, are mentioned, they are not contrasted.

(B)  is incorrect since the author’s main purpose is to support a conclusion, and, whatever refutation is offered in the passage (e.g., against the position that blood pressure in children cannot be measured accurately), it is offered in the service of a greater point.

(E)  must fail for a similar reason. And  (D)  fails for this reason as well: The author is supporting a position, not refuting it.

The correct answer is (C).

Although it is now possible to bring most high blood pressure under

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GMAT Reading Comprehension (RC) Questions

Although it is now possible to bring most high blood pressure under

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615 to 715 in 15 Days (Ria's Strategies)

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