A membrane produces an action potential whenever the potential ...

[james9437]

A membrane produces an action potential whenever the potential across it reaches what level?
 
  a. the resting potential
 b. -90 mV
 c. the threshold of excitation
  d. the refractory period

Question 2

What evidence do we have that the preoptic area controls body temperature?
 
  a. After damage to the preoptic area, an animal will simultaneously sweat and shiver.
  b. Each cell in the preoptic area has a temperature at which it is most active.
 c. Removed cells maintain a constant temperature even in a cell culture.
 d. Heating or cooling the preoptic area leads to sweating or shivering.

[cascooper22]

Answer to Question 1

c

Answer to Question 2

d

[james9437]

TYSM

[FergA]

Excellent