Final answer:
The biological process that requires hydrostatic pressure is filtration. This pressure-driven mechanism enables the movement of fluids and solutes through a semipermeable membrane, such as in the kidneys where blood plasma is filtered.
Step-by-step explanation:
The biological process that requires hydrostatic pressure is filtration. Filtration involves the movement of water and solutes through a semipermeable membrane due to the force of hydrostatic pressure, which is the pressure exerted by a fluid on a surface. In contrast, processes like osmosis, facilitated diffusion, and active transport do not utilize hydrostatic pressure in the same way.
For example, in the circulatory system, filtration allows for the movement of plasma and various substances across the glomerulus. Here, the glomerular hydrostatic pressure forces fluid and solutes into Bowman's capsule, a process vital for kidney function. This physiological filtration is dependent on the balance of hydrostatic and osmotic pressures operating across capillary membranes.