
rlm@0: Photoreceptors in the retina (such as cones) have special channels that are open to Na+ in the dark. When light hits photoreceptors, these special channels close. What can you conclude from this? 
rlm@0: a) Photoreceptors depolarize to light. 
rlm@0: b) Photoreceptors hyperpolarize to light. 
rlm@0: c) Photoreceptor voltage does not change in the presence of light.
rlm@0: d) None of the above
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rlm@0: What happens in a photoreceptor cell (a rod, for example) in response to a light stimulus?
rlm@0: a) rod membrane depolarizes because Na+ channels open as a result of a decrease in second messenger cGMP
rlm@0: b) rod membrane hyperpolarizes because K+ channels open as a result of a decrease in second messenger cGMP
rlm@0: c) rod membrane hyperpolarizes because Na+ channels close as a result of a decrease in second messenger cGMP
rlm@0: d) rod membrane depolarize because K+ channels close as a result of a increase in second messenger cGMP
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rlm@0: A difference between rods and cones is:
rlm@0: a) Rods hyperpolarize to light, while cones depolarize to light
rlm@0: b) Rods are much larger than Cones, and more numerous.
rlm@0: c) Cones and rods use different types of opsins
rlm@0: d) The total volume of all Cones is smaller than that of Rods
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rlm@0: To approximate an ideal OpAmp, all OpAmps should:
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rlm@0: a) have almost infinite positive open loop gain
rlm@0: b) have almost infinite negative open loop gain
rlm@0: c) have almost infinite positive output drift
rlm@0: d) have almost infinite negative output drift
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rlm@0: Normal OpAmps all approximate an ideal OpAmp. An Ideal OpAmp:
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rlm@0: I 		Has infinite positive open loop gain
rlm@0: II		Has zero open loop gain
rlm@0: III 	Is an IC
rlm@0: IV		Has zero output drift
rlm@0: V		Has output drift of -1
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rlm@0: 
rlm@0: a) I,III,V
rlm@0: b) II,III,V
rlm@0: c) II,V
rlm@0: d) I,IV
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rlm@0: A difference between the 741 OpAmp and the K2-W OpAmp is:
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rlm@0: a) the 741 has a large negative open loop gain while the K2-W has a large positive open loop gain
rlm@0: b) the 741 is an IC while the K2-W is not
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rlm@0: I 



