What is the function of urethra in man?

Q. Differentiate between Ureter and Urethra based on their function.

Q. In man, the sperms released from the testis take the following route to reach the urethra

Q. (i) What are the structural and functional units of kidney?
(ii) Arrange the organs of the human excretory system in the correct order, based on the passage of urine.
Ureter, Urethra, Kidney, Urinary bladder.