As much as 20 to 40 percent of the energy required by the brain ...

[fagboi]

As much as 20 to 40 percent of the energy required by the brain is used by
 
  a. sodium-potassium pumps.
 b. calcium pumps.
 c. anterograde transport within neurons.
  d. retrograde transport within neurons.

Question 2

Ion selectivity is a feature of
 
  a. both ion channels and ion pumps.
  b. neither ion channels nor ion pumps.
  c. ion channels, but not ion pumps.
 d. ion pumps, but not ion channels.

[morrie123456]

Answer to Question 1

a

Answer to Question 2

a

[fagboi]

Thanks for the timely response, appreciate it

[jojobee318]

Gracias!