In general, the frequency of APs in an afferent neuron is related to the amplitude of the receptor potential in the following way:

Question

a. exponentially.
b. there is no general relationship.
c. logarithmically.
d. linearly.

Is it exponentially? The other options make no sense.

During the rising phase of the action potential:
a. the membrane potential becomes more negative.
b. the hyperpolarization of the membrane potential brings it to threshold.
c. there is a net influx of Na+.
d. voltage-gated Na+ channels close.

I put there is a net influx of Na+

Answer 1

Both your answers are correct. Great job!

Answer 2

the first one is
b. there is no general relationship.