Question

the functional unit of the kidney is the nephron ureter urethra bladder

Explanation:

The nephron is the structural and functional unit of the kidney. It filters blood, reabsorbs useful substances, and excretes waste to form urine. The ureter transports urine from the kidney to the bladder. The urethra is the tube through which urine exits the body. The bladder stores urine.

Answer:

nephron