Symptoms of Parkinson’s Disease, such as tremors, are thought to be

Question

Symptoms of Parkinson’s Disease, such as tremors, are thought to be caused by low dopamine levels in the brain. Current treatments of Parkinson’s disease are primarily reactionary, aiming to replenish dopamine levels after dopamine-producing neurons in the brain have died. Without a more detailed understanding of the behavior of dopamine-producing neurons, it has been impossible to develop treatments that would prevent the destruction of these neurons in Parkinson’s patients.
 
Recent research provides insight into the inner workings of dopamine-producing neurons, and may lead to a new drug treatment that would proactively protect the neurons from decay. By examining the alpha-synuclein protein in yeast cells, scientists have determined that toxic levels of the protein have a detrimental effect on protein transfer within the cell. More specifically, high levels of alpha-synuclein disrupt the flow of proteins from the endoplasmic reticulum, the site of protein production in the cell, to the Golgi apparatus, the component of the cell that modifies and sorts the proteins before sending them to their final destinations within the cell. When the smooth transfer of proteins from the endoplasmic reticulum to the Golgi apparatus is interrupted, the cell dies.

With this in mind, researchers conducted a genetic screen in yeast cells in order to identify any gene that works to reverse the toxic levels of alpha-synuclein in the cell. Researchers discovered that such a gene does in fact exist, and have located the genetic counterpart in mammalian nerve cells, or neurons. This discovery has led to new hopes that drug therapy could potentially activate this gene, thereby suppressing the toxicity of alpha-synuclein in dopamine-producing neurons.

While drug therapy to suppress alpha-synuclein has been examined in yeast, fruitflies, roundworms, and cultures of rat neurons, researchers are hesitant to conclude that such therapies will prove successful on human patients. Alpha-synuclein toxicity seems to be one cause for the death of dopamine-producing neurons in Parkinson’s patients, but other causes may exist. Most scientists involved with Parkinson’s research do agree, however, that such promising early results provide a basis for further testing.   1 
 OA:E 
1) One function of the third paragraph of the passage is to

(A) highlight the many similarities between yeast cells and mammalian nerve cells
(B) explain in detail the methods used to conduct a genetic screen in yeast cells
(C) further explain the roles of various cellular components of yeast cells
(D) identify the genes in yeast cells and mammalian nerve cells that work to reverse the toxic levels of alpha-synuclein
(E) clarify the relevance of genetic testing in yeast cells to the search for a new treatment for Parkinson’s disease

2 
 OA:D 
2) It can be inferred from the passage that a yeast cell with toxic levels of alpha-synuclein will die because

(A) low levels of dopamine will disrupt the flow of proteins from the endoplasmic reticulum to the Golgi aparatus
(B) the gene that suppresses alpha-synuclein is missing or is not functioning properly in such yeast cells
(C) drug therapy has proven to be ineffective in yeast cells
(D) the normal distribution of proteins to the different cell components outside the Golgi apparatus will be affected
(E) alpha-synuclein is by nature a toxic protein

3 
 OA:C 
3) It can be inferred from the passage that current treatments of Parkinson’s Disease

(A) repair damaged cells by replenishing dopamine levels in the brain
(B) are ineffective in their treatment of Parkinson’s symptoms, such as tremors
(C) were developed without a complete understanding of dopamine-producing neurons
(D) will inevitably be replaced by new drug therapy to suppress alpha-synuclein toxicity
(E) were not developed through research on yeast cells

4 
 OA:A 
4. According to the passage, which of the following represents the chronology of a typical protein life in a healthy yeast cell?

(A) Protein is made in the endoplasmic reticulum, sent to the Golgi apparatus, processed and altered in the Golgi apparatus, and then delivered to other parts of the cell.
(B) Protein is created in the Golgi apparatus, modified and delivered to other parts of the cell, then decomposed by alpha-synuclein.
(C) Protein is produced in the endoplasmic reticulum, sent to the Golgi apparatus, and then decomposed by alpha-synuclein.
(D) Protein is produced in the Golgi apparatus, modified by the Golgi apparatus, distributed to the neuron, and then sent to the endoplasmic reticulum.
(E) Protein is produced by alpha-synuclein, transferred to the endoplasmic reticulum, sent to the Golgi apparatus for modification, and then distributed to the rest of the cell.

5 
 OA:B 
 5. The primary purpose of the passage is to

A. compare and contrast current treatments for Parkinson’s Disease
B. discuss new scientific findings and the implications of these findings for treating Parkinson’s Disease
C. explain the role of proteins in dopamine-producing neurons
D. introduce new research that supports an already existing treatment method for Parkinson’s Disease
E. question the scientific evidence used to support current treatments for Parkinson’s Disease

Source:  Manhattan Prep CAT Exam 4

Skywalker18 · Accepted Answer

1.
This is a general question asking about the function of the third paragraph. To answer this question, it is helpful to examine the general role that each paragraph in
the passage plays. The first paragraph introduces the problem: researchers have not known enough about neurons to effectively treat the symptoms of Parkinson’s Disease. The second paragraph introduces new research in yeast cells. The third paragraph makes the connection between this research and neurons affected by Parkinson’s disease. In other words, the third paragraph serves to transition from the technical detail of the yeast cell research in paragraph two to the implications of this research on Parkinson’s treatment.
(A) While the third paragraph mentions genetic counterparts in yeast cells and mammalian nerve cells, its role is not to highlight similarities between the cells. In
fact, no additional similarities are mentioned.
(B) The third paragraph does not get into the details of genetic screening methods.
(C) The third paragraph does not explain the roles of various cellular components. The second paragraph does discuss the roles of the endoplasmic reticulum and the
Golgi apparatus, but this discussion is not continued in the third paragraph.
(D) The third paragraph does not actually identify, or name, any genes. Rather, it explains that researchers were able to identify a specific gene in yeast cells and its
counterpart in mammalian nerve cells.
(E) CORRECT. The third paragraph relates the genetic testing in yeast cells to the broader issue of Parkinson’s treatment: “Researchers discovered that such a gene
does in fact exist  , and have located the genetic counterpart in mammalian nerve cells, or neurons. This discovery has led to new hopes that drug
therapy could potentially activate this gene, thereby suppressing the toxicity of alpha synuclein in dopamine-producing neurons.”

2.
This is a specific question that can be answered by examining the information given in the second paragraph.
(A) According the second paragraph, “high levels of alpha-synuclein disrupt the flow of proteins from the endoplasmic reticulum…to the Golgi apparatus,” not low levels of dopamine.
(B) While a missing or malfunctioning gene may explain why levels of alpha synuclein have risen to toxic levels in the cell, it does not explain why these high levels cause the cell to die.
(C) The effectiveness or ineffectiveness of drug therapy in yeast cells does not explain why high levels of alpha-synuclein would kill the cell. Furthermore, the fourth
paragraph suggests that drug therapy actually has been effective in yeast cells, not to mention in fruitflies, roundworms, and cultures of rat neurons.
(D) CORRECT. The second paragraph states that high levels of alpha-synuclein “disrupt the flow of proteins from the endoplasmic reticulum…to the Golgi
apparatus.” According to the passage, the Golgi apparatus is responsible for distributing proteins within the cell. It also states that "when the smooth transfer of
proteins from the endoplasmic reticulum to the Golgi apparatus is interrupted, the cell dies."
(E) The passage gives no indication that alpha-synuclein is “by nature” a toxic substance. Rather, the passage states that high levels of alpha-synuclein are toxic to
the cell.

3.
This is a specific question. We can use the key phrase “current treatments of Parkinson’s Disease” from the question to help us locate the relevant portion of the passage. The first paragraph discusses current treatments.
(A) Current treatments do not repair damaged cells. Rather, they “are primarily reactionary, aiming to replenish dopamine levels after dopamine-producing neurons
in the brain have died.”
(B) The passage does not discuss the effectiveness of current treatments.
(C) CORRECT. The first paragraph states that current treatments “replenish dopamine levels after dopamine-producing neurons in the brain have died.” It goes on to say that “without a more detailed understanding of the behavior of dopamineproducing neurons, it has been impossible to develop treatments that would prevent the destruction of these neurons in Parkinson’s patients.” We can therefore conclude that current treatments are based on an incomplete understanding of the dopamin eproducing
neuron.
(D) While the passage gives hope that new drug therapy will be effective, the fourth paragraph introduces the possibility that such treatments won’t be transferable to humans: “researchers are hesitant to conclude that such therapies will prove successful on human patients.” Thus, the claim that current treatments will inevitably be replaced by new drug therapy is unsupported by the passage.
(E) There is no information in the passage on the methods used to develop current treatments. It is very possible that yeast cells were used in researching current treatments.

4.
The second paragraph states that “high levels of alpha-synuclein disrupt the flow of proteins from the endoplasmic reticulum, the site of protein production in the cell, to
the Golgi apparatus, the component of the cell that modifies and sorts the proteins before sending them to their final destinations within the cell.” This implies that proteins in healthy cells are produced in the endoplasmic reticulum, sent to the Golgi
apparatus where they are modified, and then shipped to the rest of the cell.
(A) CORRECT. This chronology is supported by the information given in the second paragraph.
(B) Proteins are created in the endoplasmic reticulum, not the Golgi apparatus. Further, there is no evidence to show that proteins in healthy cells are decomposed
by alpha-synuclein.
(C) There is no evidence to show that proteins in healthy cells are decomposed by alpha-synuclein.
(D) Proteins are created in the endoplasmic reticulum, not the Golgi apparatus.
(E) Proteins are created in the endoplasmic reticulum, not by alpha-synuclein.

teaserbae · Answer

Skywalker18   AjiteshArun 
Can you please explain why in Q1 D is wrong 
In 3rd para Researchers discovered that such a gene does in fact exist, and have located the genetic counterpart in mammalian nerve cells, or neurons. Why cannot we infer D from it ?

teaserbae · Answer

AjiteshArun  also in Q3 why cannot we infer B since the Current treatments are primarily reactionary can't we infer they are ineffective since they cannot be done more properly until further study is done

MRAJINKYA · Answer

For people confused between answer A and D in Q2

A states that Cell dies due to low levels of dopamine, but the cells we are talking here are the dopamine producing cells. These cells dying leads to low levels of dopamine. 
This choice represents the contrast.

I made the mistake here.

Aviral1995 · Answer

Let me try to explain why in Q1 D is wrong- Since this is stated in only the first statement of para 3, while we need to see the function of whole para. Only option D would just give us the relevance of first statement and not the whole para.

Sajjad1994 · Answer

Official Explanation

5. The primary purpose of the passage is to

Explanation

The words primary purpose indicate that this is a Main Idea question that can be answered by considering the general structure of the passage.
 
 (A)  This passage does not compare and contrast current treatments. The first paragraph does mention current treatments, but these treatments are grouped together as treatments that all work to replenish dopamine levels in the brain.

(B)  CORRECT.   The topic sentence of the second paragraph discusses new scientific findings and their implications: recent research provides insight into the inner workings of dopamine-producing neurons, and may lead to a new drug treatment that would proactively protect the neurons from decay.

(C)  While the protein alpha-synuclein is discussed in the second paragraph, the role of this protein is not the main focus of the passage.

(D)  The new research method does not support an already existing treatment method, but rather a new, potential treatment method.

(E)  The scientific evidence discussed in this passage supports a new treatment method; it does not call into question currently existing treatment methods.

Answer: B

thakurarun85 · Answer

I doubt Q2 OA.

it is said in para that "When the smooth transfer of proteins from the endoplasmic reticulum to the Golgi apparatus is interrupted, the cell dies."

Now its about the smooth transfer of protean from ER to GA. Not about GA to other parts of cell (at least not mentioned in para).

What interrupt this smooth transfer is toxicity. Hence B should be the answer.

Correct me if I am wrong.

Sajjad1994 · Answer

Official Explanation

2. It can be inferred from the passage that a yeast cell with toxic levels of alpha-synuclein will die because

Difficulty Level:   Hard

Explanation

This is a specific question that can be answered by examining the information given in the second paragraph.

(A)  According to the second paragraph,  “high levels of alpha-synuclein disrupt the flow of proteins from the endoplasmic reticulum…to the Golgi apparatus,”  not low levels of dopamine.

(B)  While a missing or malfunctioning gene may explain why levels of alpha synuclein have risen to toxic levels in the cell, it does not explain why these high levels cause the cell to die.

(C)  The effectiveness or ineffectiveness of drug therapy in yeast cells does not explain why high levels of alpha-synuclein would kill the cell. Furthermore, the fourth paragraph suggests that drug therapy actually has been effective in yeast cells, not to mention in fruitflies, roundworms, and cultures of rat neurons.

(D)  CORRECT.   The second paragraph states that high levels of alpha-synuclein  “disrupt the flow of proteins from the endoplasmic reticulum…to the Golgi apparatus.”  According to the passage, the Golgi apparatus is responsible for distributing proteins within the cell. It also states that  "when the smooth transfer of proteins from the endoplasmic reticulum to the Golgi apparatus is interrupted, the cell dies."

(E)  The passage gives no indication that alpha-synuclein is “by nature” a toxic substance. Rather, the passage states that high levels of alpha-synuclein are toxic to the cell.

Answer: D

CYp113 · Answer

Q1 OE from Manhattanprep
Questions that ask about the function of certain text are Passage Structure questions. To answer this question, it is helpful to examine the general role that each paragraph in the passage plays. The first paragraph introduces the problem: researchers have not known enough about neurons to effectively treat the symptoms of Parkinson’s Disease. The second paragraph introduces new research in yeast cells. The third paragraph makes the connection between this research and neurons affected by Parkinson’s disease. In other words, the third paragraph serves to transition from the technical detail of the yeast cell research in the second paragraph to the implications of this research on Parkinson’s treatment.

(A) While the third paragraph mentions genetic counterparts in yeast cells and mammalian nerve cells, its role is not to highlight similarities between the cells. In fact, no additional similarities are mentioned.

(B) The third paragraph does not get into the details of genetic screening methods.

(C) The third paragraph does not explain the roles of various cellular components. The second paragraph does discuss the roles of the endoplasmic reticulum and the Golgi apparatus, but this discussion is not continued in the third paragraph.

(D) The third paragraph does not actually identify, or name, any genes. Rather, it explains that researchers were able to identify a specific gene in yeast cells and its counterpart in mammalian nerve cells.

(E) CORRECT. The third paragraph relates the genetic testing in yeast cells to the broader issue of Parkinson’s treatment: Researchers discovered that such a gene does in fact exist  , and have located the genetic counterpart in mammalian nerve cells, or neurons. This discovery has led to new hopes that drug therapy could potentially activate this gene, thereby suppressing the toxicity of alpha-synuclein in dopamine-producing neurons.

iamjatinagrawal · Answer

Because option D talks about GENES: (D)  identify the  GENES  in yeast cells and mammalian nerve cells that work to reverse the toxic levels of alpha-synuclein.

Whereas the third paragraph talks about a single GENE - Researchers discovered that such a  GENE.

We cannot infer GENES from GENE. Hence D is wrong.

iamjatinagrawal · Answer

From these lines in the passage:

" Current treatments of Parkinson’s disease are primarily reactionary, aiming to replenish dopamine levels after dopamine-producing neurons in the brain have died. Without a more detailed understanding of the behavior of dopamine-producing neurons... "

We cannot infer INEFFECTIVE from REACTIONARY. Reactionary doesn't mean ineffective and it's not given verbatim. Hence (B) is wrong. Also, since the current treatments are ineffective doesn't mean that they are not being done properly. We should not be assuming what's not given in the passage. We should eliminate outside information (at least in case of inference questions).

And in the above lines we can see that its given "A more detailed understanding of the ..." from which we can infer (C). Hence (C) is correct.

anthoniok · Answer

Totally agree — just because something is  reactionary  doesn’t mean it’s  ineffective . It’s a trap to conflate the two without textual evidence. GMAT loves testing that nuance.

Shadab18 · Answer

I really wanna know if this is a 655+ level passage , the questions were super easy to understand and passage wasnt challenging as well?

bb · Answer

You can see the first and second question timers have indicators of individual difficulty. Those are the ones contributing to overall difficulty of the passage.

Symptoms of Parkinson’s Disease, such as tremors, are thought to be

Prep Toolkit

Top 5 GMAT Debrief Videos

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

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Reading Comprehension (RC) Questions

Symptoms of Parkinson’s Disease, such as tremors, are thought to be

Prep Toolkit

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

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards