The nephron forms the basic functional unit of the kidney and comprises of various parts as shown in the picture.
Urine is formed by the process of ultrafiltration, and collected in the proximal tubule, from where it passes to the loop of Henle, the distal tubule and the collecting ducts, undergoing the processes of reabsorption and secretion to form the urine that is ultimately passed out. The concentration of urine so formed is governed by the water and elecrolyte balance of the body, and the required concentration is achieved by the processes mentioned above in the nephron
Fossils records the past by the very beginning of all living organism if there was wayer at one time by a fish fossil or if it was a dry land with a plant fossil
