Why is the inflow of sodium ions into a photoreceptor cell called "the dark current"?

a.) it causes photocells to stop working.
b.) it causes blindness.
c.) the inflow of ions occurs when the receptor is not receiving light.
d.) it only occurs with wavelengths outside of the visible spectrum.

The correct answer is: c.) The inflow of ions occurs when the receptor is not receiving light.

Activation of rods and cones (photoreceptor cells responsible for sight) is hyperpolarization which occurs when the light is present. In the dark, when they are not being stimulated, they depolarize and release glutamate continuously. In the dark, cells contain high concentration of cGMP, which opens sodium channels.

what are your answer choices?

tsd is temerature dependent sex determination.

tsd: it is a type of environmental sex determination in which the temperature experienced during embryonic/ larval development (ambient temperature for development) determine the sex of the offspring.

crocodile displays the tsd where the ambient temperature of the developing egg determines the individual's sex. for example in the american alligator's eggs, incubation at 33 ºc produces mostly males, while incubation at 30 ºc produces mostly females. so if the american alligator's egg will get the ambient temperature (33 degree celcius)during embryonic development from egg, the offspring will be male and same for the female sex determination.