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? 
a) Photoreceptors depolarize to light. 
b) Photoreceptors hyperpolarize to light. 
c) Photoreceptor voltage does not change in the presence of light.
d) None of the above


What happens in a photoreceptor cell (a rod, for example) in response to a light stimulus?
a) rod membrane depolarizes because Na+ channels open as a result of a decrease in second messenger cGMP
b) rod membrane hyperpolarizes because K+ channels open as a result of a decrease in second messenger cGMP
c) rod membrane hyperpolarizes because Na+ channels close as a result of a decrease in second messenger cGMP
d) rod membrane depolarize because K+ channels close as a result of a increase in second messenger cGMP


A difference between rods and cones is:
a) Rods hyperpolarize to light, while cones depolarize to light
b) Rods are much larger than Cones, and more numerous.
c) Cones and rods use different types of opsins
d) The total volume of all Cones is smaller than that of Rods






To approximate an ideal OpAmp, all OpAmps should:

a) have almost infinite positive open loop gain
b) have almost infinite negative open loop gain
c) have almost infinite positive output drift
d) have almost infinite negative output drift





Normal OpAmps all approximate an ideal OpAmp. An Ideal OpAmp:

I 		Has infinite positive open loop gain
II		Has zero open loop gain
III 	Is an IC
IV		Has zero output drift
V		Has output drift of -1


a) I,III,V
b) II,III,V
c) II,V
d) I,IV




A difference between the 741 OpAmp and the K2-W OpAmp is:

a) the 741 has a large negative open loop gain while the K2-W has a large positive open loop gain
b) the 741 is an IC while the K2-W is not






I 