Final answer:
Filtration based on blood pressure occurs in the glomerulus of the nephron.
Step-by-step explanation:
Filtration based on blood pressure occurs in the glomerulus of the nephron. The glomerulus is a network of capillaries located in the Bowman's capsule, and it is responsible for filtering blood and forming the initial filtrate.
The high blood pressure in the glomerulus forces water and small solutes out of the blood and into the tubules of the nephron. This process is known as glomerular filtration and is the first step in urine formation.