Concept:Urine formation follows a fixed order of parts in the nephron that urea passes through after filtration.
Explanation:First, urea is filtered out of the blood in the glomerulus.
This filtrate next enters Bowman's capsule.
From Bowman's capsule, it moves into the proximal convoluted tubule.
Then it flows through the loop of Henle.
After the loop, the fluid enters the distal convoluted tubule for further adjustment.
Finally, it passes into the collecting tubule, which carries urine out of the kidney.
Thus, the sequence must include two separate convoluted tubule segments: one before the loop and one after it.
Answer:Option B: glomerulus → Bowman's capsule → convoluted tubule → Henle's loop → convoluted tubule → collecting tubule.