$2$ pts

Note: This question is has $2$ parts and is worth $2$ points

Sodium ions are more concentrated on the exterior of human cells than on the interior and the interior of cells are relatively negatively charged in comparison to the exterior. Fill in the blanks for the statement below to explain how the sodium gradient is established.

The sodium gradient is established blank $1$ because the sodium ions are moved blank $2.$

blank $1$:

blank $2$:

blank $1$ options are reproduced below in case they are too long:

by simple diffusion of the ions through the membrane

by facilitated diffusion of the ions through the membrane

by coupling the unfavorable movement of sodium ions to the favorable movement of potassium ions down their concentration gradient

by coupling the unfavorable movement of sodium ions to the favorable consumption of ATP

$1$ pts