Answer: The tubule is long and highly coiled to provide a large surface area for selective reabsorption. The coiling of the tubule reduces the speed of the flow of the filtrate to give more time for efficient reabsorption. The tubule is well supplied with blood capillaries to increase a steep diffusion gradient for selective re-absorption.
Explanation: Selective reabsorption occurs because during ultrafiltration, important components of the blood are filtered out and they need to be reabsorbed into the body.