Q ​The following diagram represents a mammalian kidney tubule (nephron) and its blood
supply

Parts indicated by the guidelines 1 to 8 are as follows : 
I. Afferent arteriole from renal artery; 
2. Efferent arteriole 
3. Bowman's capsule, 
4. Glomerulus; 
5. Proximal convoluted tubule with blood capillaries; 
6. Distal convoluted tubule with blood capillaries; 
7. Collecting tubule: 
8. U-shaped loop of Henle. 
Study the diagram and answer the questions that follow : 
(a) Where does ultrafiltration take place ? 
(b) Which structure contains the lowest concentration of urea?
(c) Which structure Contains the highest Concentration of urea?
(d) Which structure (normally) contains the lowest concentration of glucose ? 
(e) Where is most water reabsorbed ?