Hi everyone,
Got 5/7 correct in 12.30 minutes, including 5 minutes to read and 7:30 minutes to answer the questions.
------------------------------------------------------------------------------------P1In paragraph one we are given that the flatfish has a special kind of asymmetry: usually this fish has both eyes either on the right or left side.
Then we are given the distributions of right eyed and left eyed flatfishes between the US and Japan: surprisingly the flatfishes close to Japan are all left eyed.
Purpose: to present the asymmetry typical of the flatfish and the distributions of such fish between US and Japan
P2In this paragraph the author introduces the point of view of biologists. They think that the asymmetry of the flatfish is adaptive. The the author asks why having both eyes on the right or on the left should result from an environmental condition, that is what is the advantage?
Purpose: to present the biologists' point of view, that is flatfish's asymmetry is adaptive
P3In paragraph 3 the author dives into the anatomy of the asymmetry. According to such studies having 2 eyes on the left or right side of the head would be disadvantageous form a mechanical point of view.
Purpose: to claim that the asymmetry is disadvantageous.
P4Here the author refutes the adaptive theory and class that there is no advantage for the flatfish in having both eyes on the right or left side of the head. Lastly the author presents the point of view of evolutionary biologists, according to whom the cause of the asymmetry is an evolutionary red herring.
Purpose: To refute the adaptive theory and to suggest another explanation for the asymmetry
Main pointTo try to provide an explanation for the asymmetry of the flatfish, evaluating a theory and refuting it in favor of another.
------------------------------------------------------------------------------------1. According to the passage, starry flounder differ from most other species of flatfish in that starry flounder
Pre-thinking
Detail question
From P1: members of the starry flounder species can be either left-eyed (both eyes on the left side of head) or right-eyed.
(A) are not basically bilaterally symmetric
(B) do not become asymmetric until adulthood
(C) do not all share the same asymmetry
(D) have both eyes on the same side of the head
(E) tend to cluster in only certain geographic regions
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2. The author would be most likely to agree with which of the following statements about left-eyedness and right-eyedness in the starry flounder?
Pre-thinking
Inference question
Let's evaluate the options
I. They are adaptive variations by the starry flounder to environmental differences.
the author disputes this theory in the last two paragraphs. See paragraphs summaries above.
II. They do not seem to give obvious selective advantages to the starry flounder.
Yes, as claimed in P3 by G. H. Parker
III. They occur in different proportions in different locations.
Correct. We can infer this option from the last sentences of P1.
(A) I only
(B) II only
(C) I and III only
(D) II and III only
(E) I, II, and III
------------------------------------------------------------------------------------3. According to the passage, a possible disadvantage associated with eye migration in flatfish is that the optic nerves can
Pre-thinking
Detail question
From P3: there would be a twisting of nerves, which might be mechanically disadvantageous.
(A) adhere to one another
(B) detach from the eyes
(C) cross
(D) stretch
(E) twist
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4. Which of the following best describes the organization of the passage as a whole?
Pre-thinking
Structure question
Introduction of the topic: bilateral asymmetry in Flounders------> proposal of a theory: Adaptability------> refutation of the theory-------> proposal of another explanation
(A) A phenomenon is described and an interpretation presented and rejected.
(B) A generalization is made and supporting evidence is supplied and weighed.
(C) A contradiction is noted and a resolution is suggested and then modified.
(D) A series of observations is presented and explained in terms of the dominant theory.
(E) A hypothesis is introduced and corroborated in the light of new evidence.
------------------------------------------------------------------------------------5. The passage supplies information for answering which of the following questions?
Pre-thinking
Detail question
Let's evaluate the options
(A) Why are Japanese starry flounder mostly left-eyed?
Never mentioned in the passage. (B) Why should the eye-sidedness in starry flounder be considered selectively neutral?
From P4: This situation is one commonly encountered by evolutionary biologists, who must often decide whether a characteristic is adaptive or selectively neutral. As for the left-eyed and right-eyed flatfish, their difference, however striking, appears to be an evolutionary red herring.
It is clear that such biologists have to make a choice. They refuted the adaptive option so it has to be the other. Later we are given the why aspect, that is an evolutionary red herring.(C) Why have biologists recently become interested in whether a characteristic is adaptive or selectively neutral?
Never mentioned(D) How do the eyes in flatfish migrate?
[b]carcass can you explain why this option is wrong? in P3 we are given how the nerves have to move so... isn't it the how aspect of the eyes' shift?[/b]
(E) How did Parker make his discoveries about the anatomy of optic nerves in flatfish?
Never mentioned ------------------------------------------------------------------------------------
. Which of the following is most clearly similar to a cline as it is described in the second paragraph of the passage?
Pre-thinking
Analogous statement question
We need to find a variation caused by environmental factors.
(A) A vegetable market in which the various items are grouped according to place of origin
(B) A wheat field in which different varieties of wheat are planted to yield a crop that will bring the maximum profit
(C) A flower stall in which the various species of flowers are arranged according to their price
(D) A housing development in which the length of the front struts supporting the porch of each house increases as houses are built up the hill
(E) A national park in which the ranger stations are placed so as to be inconspicuous, and yet as easily accessible as possible
------------------------------------------------------------------------------------7. Which of the following phrases from the passage best expresses the author's conclusion about the meaning of the difference between left -eyed and right-eyed flatfish?
Pre-thinking
Detail question
From last paragraph: As for the left-eyed and right-eyed flatfish, their difference, however striking, appears to be an evolutionary red herring.
(A) "Most striking"
(B) "variation is adaptive"
(C) "mechanically disadvantageous"
(D) "adaptively significant"
(E) "evolutionary red herring"
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