Question

a sodium ion moves into a cell against its concentration gradient. this type of transport is called.
active transport.
endocytosis.
osmosis.
passive transport.

Explanation:

Active transport is the movement of substances across a cell membrane against their concentration gradient, which requires energy. Endocytosis is bulk transport of large substances into the cell, osmosis is passive movement of water, and passive transport moves substances down their concentration gradient without energy.

Answer:

Active transport.