Light is registered in the retina

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Light is registered in the retina

by kvcpk » Fri Jul 02, 2010 5:45 am
Light is registered in the retina when photos hit molecules of the pigment rhodopsin and change the molecules' shape. Even when they have not been struck by photos of light, rhodopsin molecules sometimes change shape because of normal molecular motion, thereby introducing error into the visual system. The amount of this molecular motion is directly proportional to the temperature of the retina.

Which of the following conclusions is most strongly supported by the information above?

A. The temperature of an animal's retina depends on the amount of light the retina is absorbing.
B. The visual systems of animal whose body temperature matches that of their surroundings are more error-prone in hot surroundings than in cold ones.
C. As the temperature of the retina rises, rhodopsin molecules react more slowly to being struck by photons.
D. Rhodopsin molecules are more sensitive to photons in animals whose retinas have large surface areas than in animals whose retinas have small surface areas.
E. Molecules of rhodopsin are the only pigment molecules that occur naturally in the retina.

[spoiler]unfortunately the option I eliminated first as OOS, was the OA. Wanted to share this challenging one with all.
Source: Powerscore CR Bible[/spoiler]

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by ayushiiitm » Fri Jul 02, 2010 7:03 am
kvcpk wrote:Light is registered in the retina when photos hit molecules of the pigment rhodopsin and change the molecules' shape. Even when they have not been struck by photos of light, rhodopsin molecules sometimes change shape because of normal molecular motion, thereby introducing error into the visual system. The amount of this molecular motion is directly proportional to the temperature of the retina.

Which of the following conclusions is most strongly supported by the information above?

A. The temperature of an animal's retina depends on the amount of light the retina is absorbing.
B. The visual systems of animal whose body temperature matches that of their surroundings are more error-prone in hot surroundings than in cold ones.
C. As the temperature of the retina rises, rhodopsin molecules react more slowly to being struck by photons.
D. Rhodopsin molecules are more sensitive to photons in animals whose retinas have large surface areas than in animals whose retinas have small surface areas.
E. Molecules of rhodopsin are the only pigment molecules that occur naturally in the retina.

[spoiler]unfortunately the option I eliminated first as OOS, was the OA. Wanted to share this challenging one with all.


imo C

all other seem out of scope
Source: Powerscore CR Bible[/spoiler]
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by kvcpk » Fri Jul 02, 2010 9:15 am
Nope.. Try one more time..

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by globalcitizen » Fri Jul 02, 2010 9:56 am
I feel like its either B or D....but I am leaning toward D.

B sounds correct but I don't know if we can assume that body temperature = retina temperature.

D, however, addresses the light and temperature. Rhodopsin molecules are sensitive to light (photons) and heat (large surface area means that the retina heats up faster).

I could be totally wrong (CR is my weakest area in verbal), so I won't go into further detail without knowing the OA.

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by kvcpk » Fri Jul 02, 2010 10:14 am
globalcitizen wrote:I feel like its either B or D....but I am leaning toward D.

B sounds correct but I don't know if we can assume that body temperature = retina temperature.

D, however, addresses the light and temperature. Rhodopsin molecules are sensitive to light (photons) and heat (large surface area means that the retina heats up faster).

I could be totally wrong (CR is my weakest area in verbal), so I won't go into further detail without knowing the OA.
I should say you are half Right.. OA is B

I was stumped on this question, because, I did not want to make body temperature=retina temperature.
That was OOS for me..

I request some experts to let me know if such an assumption can be made!!

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by 786 » Sat Jul 03, 2010 2:03 am
nice question .

However , it should provide more info stating the temp of retina is directly proportional to the body temperature .

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by kvcpk » Sat Jul 03, 2010 2:13 am
786 wrote:nice question .

However , it should provide more info stating the temp of retina is directly proportional to the body temperature .
Yeah.. I was expecting the same..

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by ikaplan » Fri Nov 26, 2010 4:34 am
This is Must Be True question.

I discarded A, B and D because they refer to animal's retina. Since this is a Must Be True question, no outside information should be brought into the answer choices and "animal" is not mentioned in the stimulus. This is what really confused me in this question
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by kevincanspain » Fri Nov 26, 2010 6:25 am
kvcpk wrote:Light is registered in the retina when photos hit molecules of the pigment rhodopsin and change the molecules' shape. Even when they have not been struck by photos of light, rhodopsin molecules sometimes change shape because of normal molecular motion, thereby introducing error into the visual system. The amount of this molecular motion is directly proportional to the temperature of the retina.

Which of the following conclusions is most strongly supported by the information above?

A. The temperature of an animal's retina depends on the amount of light the retina is absorbing.
B. The visual systems of animal whose body temperature matches that of their surroundings are more error-prone in hot surroundings than in cold ones.
C. As the temperature of the retina rises, rhodopsin molecules react more slowly to being struck by photons.
D. Rhodopsin molecules are more sensitive to photons in animals whose retinas have large surface areas than in animals whose retinas have small surface areas.
E. Molecules of rhodopsin are the only pigment molecules that occur naturally in the retina.

Read B carefully... If the visual system of an animal (the retina is part of this system) is at a temperature equal to that of the surroundings, the last sentence of the text suggests that B is true

[spoiler]unfortunately the option I eliminated first as OOS, was the OA. Wanted to share this challenging one with all.
Source: Powerscore CR Bible[/spoiler]
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by abhishric » Sat Jul 02, 2011 2:29 am
I agree, there must be no extra information inserted in the 'must be true' questions and hence A, B and D can be negated...my answer is 'C'

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by Sanjay2706 » Sat Jul 02, 2011 3:18 am
IMO D.
What's the OA?

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by abhishric » Sat Jul 02, 2011 3:35 am
Sanjay2706 wrote:IMO D.
What's the OA?
it's 'B'. And that cleraly introduces external information in the conclusion(The visual systems of animals whose).

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by mriiidula » Sat Jul 02, 2011 4:53 am
IMO B. I guess you cant assume retina temperature = body temperature (even though I did, oops!), but none of the other answers fit, so it has to be B, right?
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by mirantdon » Sat Jul 02, 2011 7:10 am
+1 for B.
Must be true question