What is the process of filtration?

The process of filtration is best described as the movement of particles from an area of high pressure to an area of low pressure. This process relies on the pressure difference to drive the separation of particles, typically involving a membrane or filter that allows certain particles to pass while blocking others.

In a biological context, filtration occurs in the kidneys, where blood pressure forces water and solutes through the glomerular membrane into the nephrons, forming urine. This mechanism is crucial for maintaining fluid balance and waste removal in the body.

The other options relate to different processes: the movement of particles from low to high pressure describes a type of active transport that requires energy, while diffusion involves particles moving from areas of high concentration to low concentration without the influence of pressure. Absorption describes a different process where substances are absorbed through a membrane rather than being filtered based on pressure differences. Understanding these distinctions is important in the context of fluid dynamics and biological systems.