Light is registered in the retina when photons hit molecules of the pigment rhodopsin and change the molecules' shape. Even when they have not been struck by photons of light, rhydopsin 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 one 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 animals 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.
Explain your answer.
ok guys, the OA here is B. I have to admit, this problem is a tough one, probably in a 40+ level. Although temperature is not directly mentioned, it is somehow implied. How? Well, in the first sentence of the argument, it says "Light is registered in the retina when photons hit molecules of the pigment rhodopsin and change the molecules' shape." The difficulty here is to recognize the fact that light contains heat. Now if you didn't realize that, obviously you would be struggling when choosing an answer choice. Since you couldn't find "light" among the answer choices, you have to pause there for a second and realize the fact that our subject has been translated into another form. We should all know that light is in fact heat.
since the argument says that the shape of the molecules can still change even when not struck by light, then another form of heat besides light can still achieve a similar impact. That's what option B does.
Option C is wrong because we don't know whether heat will change the shape of molecules slowly or quickly. The only thing we know is that the shape will in fact change. However, how fast can it change remains a mystery.
hope this helps