The concentration of calcium in a cell is 0.3%. The concentration of calcium in the surrounding fluid is 0.1%. How could the cell obtain more calcium?

Primary active transport

Explanation:

In a cell, the movement of molecules like calcium ions (Ca²⁺), to a region having high solute concentration from a region having low solute concentration, through the cell membrane requires metabolic energy and is known as Primary active transport.

It is given that the concentration of calcium in the cell (0.3%) is greater than the concentration of calcium in the fluid surrounding the cell (0.1%). So the calcium ions move into the cell and the cell obtains more calcium.

Therefore, the cell obtains more calcium by the process of Primary active transport.