Protein synthesis begins when the gene encoding a protein is activated

Question

Protein synthesis begins when the gene encoding a protein is activated. The gene’s sequence of nucleotides is transcribed into a molecule of messenger RNA (mRNA), which reproduces the information contained in that sequence. Transported outside the nucleus to the cytoplasm, the mRNA is translated into the protein it encodes by an organelle known as a ribosome, which strings together amino acids in the order specified by the sequence of elements in the mRNA molecule. Since the amount of mRNA in a cell determines the amount of the corresponding protein, factors affecting the abundance of mRNA’s play a major part in the normal functioning of a cell by appropriately regulating protein synthesis. For example, an excess of certain proteins can cause cells to proliferate abnormally and become cancerous; a lack of the protein insulin results in diabetes.

Biologists once assumed that the variable rates at which cells synthesize different mRNA’s determine the quantities of mRNA’s and their corresponding proteins in a cell. However, recent investigations have shown that the concentrations of most mRNA’s correlate best, not with their synthesis rate, but rather with the equally variable rates at which cells degrade the different mRNA’s in their cytoplasm. If a cell degrades both a rapidly and a slowly synthesized mRNA slowly, both mRNA’s will accumulate to high levels.

An important example of this phenomenon is the development of red blood cells from their unspecialized parent cells in bone marrow. For red blood cells to accumulate sufficient concentrations of hemoglobin (which transports oxygen) to carry out their main function, the cells’ parent cells must simultaneously produce more of the constituent proteins of hemoglobin and less of most other proteins. To do this, the parent cells halt synthesis of non-hemoglobin mRNA’s in the nucleus and rapidly degrade copies of the non-hemoglobin mRNA’s remaining in the cytoplasm. Halting synthesis of mRNA alone would not affect the quantities of proteins synthesized by the mRNA’s still existing in the cytoplasm. Biologists now believe that most cells can regulate protein production most efficiently by varying both mRNA synthesis and degradation, as developing red cells do, rather than by just varying one or the other.   1 
 1. The passage is primarily concerned with discussing the

(A) influence of mRNA concentrations on the development of red blood cells
(B) role of the synthesis and degradation of mRNA in cell functioning
(C) mechanism by which genes are transcribed into mRNA
(D) differences in mRNA concentrations in cell nuclei and in the cytoplasm
(E) way in which mRNA synthesis contributes to the onset of diabetes

2 
 2. The passage suggests that a biologist who held the view described in the first sentence of the second paragraph would most probably also have believed which of the following?

(A) The rate of degradation of specific mRNA’s has little effect on protein concentrations.
(B) The rate of degradation of specific mRNA’s should be studied intensively.
(C) The rates of synthesis and degradation for any given mRNA are normally equal.
(D) Different mRNA’s undergo degradation at widely varying rates.
(E) Most mRNA’s degrade very rapidly.

3 
 3. Which of the following best describes the relationship between the second and third paragraphs of the passage?

(A) The second paragraph presents arguments in support of a new theory and the third paragraph presents arguments against that same theory.
(B) The second paragraph describes a traditional view and the third paragraph describes the view that has replaced it on the basis of recent investigations.
(C) The third paragraph describes a specific case of a phenomenon that is described generally in the second paragraph.
(D) The third paragraph describes an investigation that was undertaken to resolve problems raised by phenomena described in the second paragraph.
(E) Both paragraphs describe in detail specific examples of the phenomenon that is introduced in the first paragraph.

4 
 4. The accumulation of concentrations of hemoglobin in red blood cells is mentioned in the passage as an example of which of the following?

(A) The effectiveness of simultaneous variation of the rates of synthesis and degradation of mRNA
(B) The role of the ribosome in enabling a parent cell to develop properly into a more specialized form
(C) The importance of activating the genes for particular proteins at the correct moment
(D) The abnormal proliferation of a protein that threatens to make the cell cancerous
(E) The kind of evidence that biologists relied on for support of a view of mRNA synthesis that is now considered obsolete

5 
 5. To begin to control a disease caused by a protein deficiency, the passage suggests that a promising experimental treatment would be to administer a drug that would reduce

(A) only the degradation rate for the mRNA of the protein involved
(B) only the synthesis rate for the mRNA of the protein involved
(C) both the synthesis and degradation rates for the mRNA of the protein involved
(D) the incidence of errors in the transcription of mRNA’s from genetic nucleotide sequences
(E) the rate of activity of ribosomes in the cytoplasm of most cells

6 
 6. According to the passage, which of the following best describes the current view on the relationship between the synthesis and the degradation of mRNA in regulating protein synthesis?

(A) Biologists have recently become convinced that the ribosome controls the rates of synthesis and degradation of mRNA.
(B) There is no consensus among biologists as to the significance of mRNA degradation in regulating protein synthesis.
(C) The concept of mRNA degradation is so new that most biologists still believe that the vital role in protein regulation belongs to mRNA synthesis.
(D) Degradation of mRNA is now considered to be the key process and mRNA synthesis is no longer believed to play a significant role.
(E) Degradation of mRNA is now considered to be as important as mRNA synthesis has been, and still is, believed to be.

7 
 7. According to the passage, which of the following can happen when protein synthesis is not appropriately regulated?

(A) Diabetes can result from errors that occur when the ribosomes translate mRNA into protein.
(B) Cancer can result from an excess of certain proteins and diabetes can result from an insulin deficiency.
(C) A deficiency of red blood cells can occur if bone marrow cells produce too much hemoglobin.
(D) Cancer can be caused by excessively rapid degradation of certain amino acids in the cytoplasm of cells.
(E) Excessive synthesis of one protein can trigger increased degradation of mRNA’s for other proteins and create severe protein imbalances.

8 
 8. The passage suggests that a biologist who detected high levels of two proteins in a certain type of cell would be likely to consider which of the following as a possible explanation?

(A) The rate of mRNA degradation for one of the proteins increases as this type of cell develops a more specialized function.
(B) The two proteins are most likely constituents of a complex substance supporting the cells’ specialized function.
(C) The cells are likely to proliferate abnormally and possibly become cancerous due to the levels of these proteins.
(D) The mRNA’s for both proteins are being degraded at a low rate in that type of cell.
(E) The mRNA’s for the two proteins are being synthesized at identical rates in that type of cell.

blueseas · Accepted Answer

I always get lost in the details in such passages and hence make mistakes in inference questions.
Could anyone help me how can we attempt these kind of passages.

Below are some specific doubts. 
 HI ,
IT IS LIKE THIS :
CELLS synthesize mRNA==>mRNA produces protein in cell.
now in second paragraph if you read the highlited part:

Biologists once assumed that the variable rates at which cells synthesize different mRNA’s determine the quantities of mRNA’s and their corresponding proteins in a cell. However, recent investigations have shown that the concentrations of most mRNA’s correlate best, not with their synthesis rate, but rather with the equally variable rates at which cells degrade the different mRNA’s in their cytoplasm.  If a cell degrades both a rapidly and a slowly synthesized mRNA slowly, both mRNA’s will accumulate to high levels.

so its saying if you want to increase level of mRNA the cell should degrade it slowly.
if degradation is slow==>more mRNA will accumulate and hence more protein will develop.
so as in question 5 ==>there is a protein deficincy ..and that can be improved only by reducing the degradation rate.....hence A .

QUESTION 7 has answer in the last line of the first paragraph:
an excess of certain proteins can cause cells to proliferate abnormally and become cancerous; a lack of the protein insulin results in diabetes. ===>hence B

QUESTION 8:
AGAIN FOR THIS AS WE KNOW IF THERE IS EXCESS LEVEL OF SOMETHING THEN DEGRADATION WILL BE LOW AS STATED IN THE HIGHLITED AREA OF SECOND PARAGRAPH.
HENCE D

EMPOWERgmatVerbal · Answer

Your questions are perfectly understandable for THIS passage for two reasons that are worth keeping in mind: 1) On the official GMAT, you’ll either see 3 or 4 questions associated with a passage, and NEVER 8 as is the case in this passage. In the GMAT Official Guide, you’ll often see more than 4 questions associated with a passage, but that’s because GMAC is sharing a greater range of questions from the pool authored for that passage. 2) In terms of technicality, this passage goes off-the-charts. Official passages can get technical as is exemplified by the plant hormone passage in the OG 2015 (passage-24-all-of-the-cells-in-a-particular-plant-start-out-4681.html), but that tends to be the exception. Furthermore, and generally speaking, the more complex the passage, the more general the questions associated with that passage tend to be. There are definitely exceptions, as is exemplified by the snake passage(in-terrestrial-environments-gravity-places-special-demands-137034.html) (in which many of the questions require a firm understanding of the specifics of the 3 different snake species referenced in the passage), but a far more common example of how official questions relate to a passage is the Gold Quartz Vein passage (according-to-a-recent-theory-archean-age-gold-quartz-vein-136458.html). The Gold passage is highly technical, yet nearly all of the questions are shockingly general, and the right options are fantastically common sense oriented if the passage is read with the EMPOWERgmat tactics. General RC Pacing Guidelines There is far more to proper RC pacing than what follows (to read and “ladder” a passage properly), but here is the RC pacing guideline for those shooting for at least 600+: Passage : 3-4 Minutes (skimming or reading only certain parts of a passage is useful for those with a mid-range score goal, but for those shooting for 700+, it’s impossible to skim AND crush RC). The basic instinct is to skim to save time, but you’re far better off investing some more time up front reading critically, and taking interest in the passage because: a) Your performance will be dramatically better, and b) So will your pacing since you’ll be able to answer the questions faster. It’s far easier to dismiss the 4 wrong options with a firm grasp of the passage and the author’s agenda. Questions : About 1.5 minutes, on average . That’s an average, of course. Passage Purpose questions can take about 1 minute, and a Detail EXCEPT question, for example, can take up to 2 minutes. By that count, this passage and ALL 8 questions (essentially 2 passages worth of questions) would reasonably take: 4 minutes to read and ladder the passage 12 Minutes to answer all 8 questions (8 x 1.5 Minutes) Benchmark Time : 16 Minutes And to reiterate, the official passages only have up to 4 questions, and not 8 as this passage does. On a real GMAT passage, the pacing benchmark/limit is : 3 Question Passage Up to 4 Minutes to Read and Ladder 4.5 Minutes to answer the questions (3 x 1.5 minutes) Total Time : 8.5 Minutes 4 Question Passage Up to 4 Minutes to Read and Ladder 6 Minutes to answer the questions (4 x 1.5 minutes) Total Time : 10 Minutes

anukrati · Answer

Protein synthesis begins when the gene encoding a protein is activated. The gene’s sequence of nucleotides is transcribed into a molecule of messenger RNA (mRNA), which reproduces the information contained in that sequence. Transported outside the nucleus to the cytoplasm, the mRNA is translated into the protein it encodes by an organelle known as a ribosome, which strings together amino acids in the order specified by the sequence of elements in the mRNA molecule. Since the amount of mRNA in a cell determines the amount of the corresponding protein, factors affecting the abundance of mRNA’s play a major part in the normal functioning of a cell by appropriately regulating protein synthesis. For example, an excess of certain proteins can cause cells to proliferate abnormally and become cancerous; a lack of the protein insulin results in diabetes.

Biologists once assumed that the variable rates at which cells synthesize different mRNA’s determine the quantities of mRNA’s and their corresponding proteins in a cell. However, recent investigations have shown that the concentrations of most mRNA’s correlate best, not with their synthesis rate, but rather with the equally variable rates at which cells degrade the different mRNA’s in their cytoplasm. If a cell degrades both a rapidly and a slowly synthesized mRNA slowly, both mRNA’s will accumulate to high levels.

An important example of this phenomenon is the development of red blood cells from their unspecialized parent cells in bone marrow. For red blood cells to accumulate sufficient concentrations of hemoglobin (which transports oxygen) to carry out their main function, the cells’ parent cells must simultaneously produce more of the constituent proteins of hemoglobin and less of most other proteins. To do this, the parent cells halt synthesis of non-hemoglobin mRNA’s in the nucleus and rapidly degrade copies of the non-hemoglobin mRNA’s remaining in the cytoplasm. Halting synthesis of mRNA alone would not affect the quantities of proteins synthesized by the mRNA’s still existing in the cytoplasm. Biologists now believe that most cells can regulate protein production most efficiently by varying both mRNA synthesis and degradation, as developing red cells do, rather than by just varying one or the other.  1. The passage is primarily concerned with discussing the 
(A) influence of mRNA concentrations on the development of red blood cells 
(B) role of the synthesis and degradation of mRNA in cell functioning 
(C) mechanism by which genes are transcribed into mRNA 
(D) differences in mRNA concentrations in cell nuclei and in the cytoplasm 
(E) way in which mRNA synthesis contributes to the onset of diabetes 
 1 
 B

2. The passage suggests that a biologist who held the view described in the first sentence of the second paragraph would most probably also have believed which of the following? 
(A) The rate of degradation of specific mRNA’s has little effect on protein concentrations. 
(B) The rate of degradation of specific mRNA’s should be studied intensively. 
(C) The rates of synthesis and degradation for any given mRNA are normally equal. 
(D) Different mRNA’s undergo degradation at widely varying rates. 
(E) Most mRNA’s degrade very rapidly. 
 2 
 A

3. Which of the following best describes the relationship between the second and third paragraphs of the passage? 
(A) The second paragraph presents arguments in support of a new theory and the third paragraph presents arguments against that same theory. 
(B) The second paragraph describes a traditional view and the third paragraph describes the view that has replaced it on the basis of recent investigations. 
(C) The third paragraph describes a specific case of a phenomenon that is described generally in the second paragraph. 
(D) The third paragraph describes an investigation that was undertaken to resolve problems raised by phenomena described in the second paragraph. 
(E) Both paragraphs describe in detail specific examples of the phenomenon that is introduced in the first paragraph. 
 3 
 C

4. The accumulation of concentrations of hemoglobin in red blood cells is mentioned in the passage as an example of which of the following? 
(A) The effectiveness of simultaneous variation of the rates of synthesis and degradation of mRNA 
(B) The role of the ribosome in enabling a parent cell to develop properly into a more specialized form 
(C) The importance of activating the genes for particular proteins at the correct moment 
(D) The abnormal proliferation of a protein that threatens to make the cell cancerous 
(E) The kind of evidence that biologists relied on for support of a view of mRNA synthesis that is now considered obsolete 
 4 
 A

5. To begin to control a disease caused by a protein deficiency, the passage suggests that a promising experimental treatment would be to administer a drug that would reduce 
(A) only the degradation rate for the mRNA of the protein involved 
(B) only the synthesis rate for the mRNA of the protein involved 
(C) both the synthesis and degradation rates for the mRNA of the protein involved 
(D) the incidence of errors in the transcription of mRNA’s from genetic nucleotide sequences 
(E) the rate of activity of ribosomes in the cytoplasm of most cells 
 5 
 A

6. According to the passage, which of the following best describes the current view on the relationship between the synthesis and the degradation of mRNA in regulating protein synthesis? 
(A) Biologists have recently become convinced that the ribosome controls the rates of synthesis and degradation of mRNA. 
(B) There is no consensus among biologists as to the significance of mRNA degradation in regulating protein synthesis. 
(C) The concept of mRNA degradation is so new that most biologists still believe that the vital role in protein regulation belongs to mRNA synthesis. 
(D) Degradation of mRNA is now considered to be the key process and mRNA synthesis is no longer believed to play a significant role. 
(E) Degradation of mRNA is now considered to be as important as mRNA synthesis has been, and still is, believed to be. 
 6 
 E

7. According to the passage, which of the following can happen when protein synthesis is not appropriately regulated? 
(A) Diabetes can result from errors that occur when the ribosomes translate mRNA into protein. 
(B) Cancer can result from an excess of certain proteins and diabetes can result from an insulin deficiency. 
(C) A deficiency of red blood cells can occur if bone marrow cells produce too much hemoglobin. 
(D) Cancer can be caused by excessively rapid degradation of certain amino acids in the cytoplasm of cells. 
(E) Excessive synthesis of one protein can trigger increased degradation of mRNA’s for other proteins and create severe protein imbalances. 
 7 
 B

8. The passage suggests that a biologist who detected high levels of two proteins in a certain type of cell would be likely to consider which of the following as a possible explanation? 
(A) The rate of mRNA degradation for one of the proteins increases as this type of cell develops a more specialized function. 
(B) The two proteins are most likely constituents of a complex substance supporting the cells’ specialized function. 
(C) The cells are likely to proliferate abnormally and possibly become cancerous due to the levels of these proteins. 
(D) The mRNA’s for both proteins are being degraded at a low rate in that type of cell. 
(E) The mRNA’s for the two proteins are being synthesized at identical rates in that type of cell. 
 8 
 D

I always get lost in the details in such passages and hence make mistakes in inference questions. 
Could anyone help me how can we attempt these kind of passages.

Below are some specific doubts.

Question 5 -

I marked C as the answer but the correct answer is not that. 
While we talk about protein deficiency in the last line of first passage but we are nowhere talking about how to overcome that. 
Also in the passage we are talking about varying the synthesis as well as degradation rate and hence I selected Option C. 
Could anyone explain this answer and also the flaw in my reasoning.

Question 7 and 8.

I got these two question also incorrect. 
Can anyone explain me each answer choice.

Thanks

GMATPill · Answer

#7 "According to the passage..."

So using the GMATPill RC technique, you want to find instances in the passage that talk about the relevant topic, then dive further for detailed information. Using that detailed information, try to answer the question.

GMATPill Tip:   So we know we have to find instances where they talk about the relevant topic - "when protein synthesis is not appropriately regulated"

Well we have a keyword phrase:
"Since the amount of mRNA in a cell determines the amount of the corresponding protein" -- well this is a hint as to protein production -- which is relevant to "protein synthesis" in the question stem.

So what happens when protein production/synthesis is not regulated?  Well if we read on a little bit here since they are talking about protein production and the question stem is about protein production...

...we'll see that the rest of the sentence talks about "appropriately regulating protein synthesis".

Great, we're still on the same topic.

The sentence following that talks about "an excess of certain proteins" -- BINGO. This keyword "excess" is synonymous to "not appropriately regulated". What happens in this case? The last sentence of the first paragraph:

"an excess of certain proteins can cause cells to proliferate abnormally and become cancerous; a lack of the protein insulin results in diabetes." -- the first part of that sentence is important. "Not appropriately regulated" leads to "cancerous".

Answer choice (B) says "cancer can result from an excess of certain proteins and diabetes can result from an insulin deficiency..."  -- that's the answer. It's worded exactly as we see it in the last sentence of paragraph 1.

7. According to the passage, which of the following can happen when protein synthesis is not appropriately regulated? 
(A) Diabetes can result from errors that occur when the ribosomes translate mRNA into protein. 
(B) Cancer can result from an excess of certain proteins and diabetes can result from an insulin deficiency. 
(C) A deficiency of red blood cells can occur if bone marrow cells produce too much hemoglobin. 
(D) Cancer can be caused by excessively rapid degradation of certain amino acids in the cytoplasm of cells. 
(E) Excessive synthesis of one protein can trigger increased degradation of mRNA’s for other proteins and create severe protein imbalances.

Answer choice (A) might get you tricked up.   Itsays "diabetes can result..." -- yes that's one of the side effects of "excess proteins" but the details are not right. "Diabetes can result from errors that occur when the ribosomes translate mRNA into protein." -- well the last sentence of paragraph 1 does not talk about errors occurring from translation so this is not directly supported. Diabetes resulting from insulin deficiency is supported but NOT the diabetes resulting from translation errors. So you can just jump to the answer choice once you see something your recognize "diabetes" -- instead you have to read the whole answer choice and the check the reasoning. Make sure it is fully supported by information in the specific area of the passage that you are reading.

nandeta · Answer

1. The passage is primarily concerned with discussing the
(A) influence of mRNA concentrations on the development of red blood cells
Wrong. Only in one paragraph and that also as an example.

(B) role of the synthesis and degradation of mRNA in cell functioning
  Correct. The story is connecting to each other.

(C) mechanism by which genes are transcribed into mRNA
Wrong. Only in first paragragh. Serves as an introduction.

(D) differences in mRNA concentrations in cell nuclei and in the cytoplasm
Wrong. Mentioned only in one sentence.

(E) way in which mRNA synthesis contributes to the onset of diabetes
Wrong. Mentioned only in one paragraph.

2. The passage suggests that a biologist who held the view described in the first sentence of the second paragraph would most probably also have believed which of the following?

(A) The rate of degradation of specific mRNA’s has little effect on protein concentrations.
  Right, they believed that cells synthesis at variable rates tells about it's corresponding proteins.
So it is assumed that they must have neglected the role of degradation.. it was only later it was 
discovered that degradation has a major role.

(B) The rate of degradation of specific mRNA’s should be studied intensively.
Wrong. They already studied it.

(C) The rates of synthesis and degradation for any given mRNA are normally equal.
Wrong. This is mentioned in the last paragraph.

(D) Different mRNA’s undergo degradation at widely varying rates.
Wrong. Mentioned in the last paragraph.

3. Which of the following best describes the relationship between the second and third paragraphs of the passage?

(A) The second paragraph presents arguments in support of a new theory and the third paragraph presents arguments against that same theory.
Wrong. The third paragraph presents an example to justify it.

(B) The second paragraph describes a traditional view and the third paragraph describes the view that has replaced it on the basis of recent investigations.
Wrong. Second paragraph describes the tradtional view and the new theory against it.

(C) The third paragraph describes a specific case of a phenomenon that is described generally in the second paragraph.
  Correct. Argument and new case finding is described in second paragraph and an example is given in third paragraph.

(D) The third paragraph describes an investigation that was undertaken to resolve problems raised by phenomena described in the second paragraph.
Wrong. This was my answer choice but when i reviewed it, i felt it was my fault. There were no problems raised to resolve.
It was already resolved and an example was presented.

(E) Both paragraphs describe in detail specific examples of the phenomenon that is introduced in the first paragraph.
Nope. Second paragraph describes the phenomena and third paragraph introduces an example for it.

(E) Most mRNA’s degrade very rapidly.
Wrong. Out of context.

4. The accumulation of concentrations of hemoglobin in red blood cells is mentioned in the passage as an example of which of the following?

(A) The effectiveness of simultaneous variation of the rates of synthesis and degradation of mRNA
  Right. Mentioned in the last paragraph. "protein production most efficiently by varying both mRNA synthesis and degradation, 
as developing red cells do, rather than by just varying one or the other."

(B) The role of the ribosome in enabling a parent cell to develop properly into a more specialized form
Wrong. Out of context.

(C) The importance of activating the genes for particular proteins at the correct moment
Wrong. This is related to gene ecoding to form a thread of protein.

(D) The abnormal proliferation of a protein that threatens to make the cell cancerous
Wrong. This happens dude exceess of protein.

(E) The kind of evidence that biologists relied on for support of a view of mRNA synthesis that is now considered obsolete
Wrong. Out of context.

5. To begin to control a disease caused by a protein deficiency, the passage suggests that a promising experimental 
treatment would be to administer a drug that would reduce

(A) only the degradation rate for the mRNA of the protein involved
  Correct. Reducing the degradation level would ensure that protein would not be deficient.

(B) only the synthesis rate for the mRNA of the protein involved
Wrong. If we reduced the synthesis rate for the protein that would mean that protein would be deficient.

(C) both the synthesis and degradation rates for the mRNA of the protein involved
Nope. They should be inverse. Increase the synthesis and decrease the degradation

(D) the incidence of errors in the transcription of mRNA’s from genetic nucleotide sequences
Wrong. Nothing to do with the protein deficiency.

(E) the rate of activity of ribosomes in the cytoplasm of most cells
Wrong. Out of context.

6. According to the passage, which of the following best describes the current view on the relationship between the synthesis and the degradation of mRNA in regulating protein synthesis?

(A) Biologists have recently become convinced that the ribosome controls the rates of synthesis and degradation of mRNA.
Wrong. Ribosome does not control the rates.

(B) There is no consensus among biologists as to the significance of mRNA degradation in regulating protein synthesis.
Wrong. They have reached a final verdict in paragraph 2.

(C) The concept of mRNA degradation is so new that most biologists still believe that the vital role in protein regulation belongs to mRNA synthesis.
Wrong. In second paragraph they are convinced that degradation is as important as synthesis.]

(D) Degradation of mRNA is now considered to be the key process and mRNA synthesis is no longer believed to play a significant role.
Wrong. Both play equal parts in the key process of a cell.

(E) Degradation of mRNA is now considered to be as important as mRNA synthesis has been, and still is, believed to be.
  Correct. They reached this verdict in the second paragraph last line.

7. According to the passage, which of the following can happen when protein synthesis is not appropriately regulated?

(A) Diabetes can result from errors that occur when the ribosomes translate mRNA into protein.
Wrong. Diabetes happen there is a lack of protein.

(B) Cancer can result from an excess of certain proteins and diabetes can result from an insulin deficiency.
  Correct. First paragraph last sentence.

(C) A deficiency of red blood cells can occur if bone marrow cells produce too much hemoglobin.
Wrong. Not mentioned in the paragraph.

(D) Cancer can be caused by excessively rapid degradation of certain amino acids in the cytoplasm of cells.
Wrong. Cancer can be caused by excess of protein.

(E) Excessive synthesis of one protein can trigger increased degradation of mRNA’s for other proteins and create severe protein imbalances.
Wrong. This creates balnce. Increase of one and decrease of another.

8. The passage suggests that a biologist who detected high levels of two proteins in a certain type of cell would be likely to consider which of the following as a possible explanation?

(A) The rate of mRNA degradation for one of the proteins increases as this type of cell develops a more specialized function.
Wrong. The passage does not suggets anything about the complex function.

(B) The two proteins are most likely constituents of a complex substance supporting the cells’ specialized function.
Wrong. The passage does not talk about specialized cell function.

(C) The cells are likely to proliferate abnormally and possibly become cancerous due to the levels of these proteins.
Wrong. This only talks about one type of protein.

(D) The mRNA’s for both proteins are being degraded at a low rate in that type of cell.
  Correct. If a cell degrades both a rapidly and a slowly synthesized mRNA slowly, both mRNA’s will accumulate to high levels.

(E) The mRNA’s for the two proteins are being synthesized at identical rates in that type of cell.
Wrong. When detected high level, the cells will try to decrease it on it's own

JOBS07 · Answer

EMPOWERgmatVerbal   Sajjad1994   GMATNinja   KarishmaB

In Q3, Can you please guide me why option B is wrong ? It might seem simple, given that passage 3 starts the phrase "An important example...". However, My concerns are:

1) The ending of para 2 - "However, recent investigations have shown that the concentrations of most mRNA’s  correlate best, not with their synthesis rate, but rather with the equally variable rates at which cells degrade  the different mRNA’s in their cytoplasm.  If a cell degrades both a rapidly and a slowly synthesized mRNA slowly, both mRNA’s will accumulate to high levels. "

The opinion seems to be that the degradation rate plays a more important role than synthesis rate.

2) Ending of para 3 - Biologists now believe that  most cells can regulate protein production most efficiently by varying both mRNA synthesis and degradation , as developing red cells do,  rather than by just varying one or the other.

Query - The above seems to imply that both production and degradation play role in efficient regulation of the content in the cell vs the hypothesis that degradation plays more imp role. Also the example of RBC and bone marrow does not exemplify the opinion at the end of 2nd paragraph, as ,again, its implying that both play an important role. Its more an example of the opinion at end of passage.

Requesting your inputs,
Thanks

YuktiMaheshwari · Answer

GMATNinja   KarishmaB  : Could you please explain question 5?

GMATNinja · Answer

Question 3 
 
Paragraph 3 doesn't say that synthesis and degradation have an equal impact on protein production. It simply states that cells can regulate protein production  most efficiently  by varying both. That can be true even if concentrations of most mRNA’s correlate BEST with degradation rates (as discussed in paragraph 2).

In other words, the new info in paragraph 3 supplements paragraph 2, but doesn't contradict it.

More importantly, (B) has to go because it doesn't describe the "traditional" view. Instead, it talks about RECENT investigations and their implications.

(C) is a better fit. As you said, RBC is cited as an example of the phenomenon described in paragraph 2, so we know that the two paragraphs aren't talking about two different views.

I hope that helps!

GMATNinja · Answer

Question 5

If the concern is protein deficiency, then we'd want to figure out how to increase the amount of the protein. You could do that one of two ways:
 
 Reduce the amount of degradation, or
 
 Increase the amount of synthesis

If you aren't being careful, you might accidentally pick (C) here. But notice that the question specifically refers to a drug that would  reduce  ____. And since we only want to REDUCE degradation (remember, we'd want to INCREASE synthesis), (A) is the right one.

I hope that helps!

krysss · Answer

hi, could u plz tell where we can find the illustration about how can we control the protein deficiency?

GMATNinja · Answer

This particular situation (trying to control a disease caused by protein deficiency) isn't specifically described in the passage. But the passage -- particularly the 2nd and 3rd paragraphs -- talk a lot about controlling protein levels.

Obviously, one factor affecting protein levels is the rate at which the protein is produced (the synthesis rate). But a more significant factor is the rate at which the protein is destroyed in the cytoplasm (the degradation rate).

Now let's apply that to the hypothetical situation posed by question 5:

There's a disease caused by protein DEFICIENCY. To control that disease, we need to address that deficiency by INCREASING the amount of protein.
 
 How can we increase the amount of protein? As listed above in red, we can 1) reduce the amount of degradation, or 2) increase the amount of synthesis.
 
 As described in our previous post, the question specifically asks about REDUCING something. Since we want to REDUCE degradation, (A) is the right choice.
 
 Side note: the passage suggests that INCREASING the amount of synthesis might not have much of an effect on protein levels -- degradation rate seems to be the more significant factor.

I hope that helps!

VerbalBot · Answer

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Protein synthesis begins when the gene encoding a protein is activated

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Protein synthesis begins when the gene encoding a protein is activated

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