An adult human excretes,on average,... liters of urine per day. On an average,... of urea is excreted out per day.

Urea enters the nephron through . . . . . . .
$i$. Thicker segment of ascending limb of Henle's loop.
$ii$. Thinner segment of ascending limb of Henle's loop.
$iii$. Ultrafiltration into urinary space.
$iv$. Inner medullary segment of collecting tubule.
$v$. Outer medullary segment of collecting tubule.
Select the correct option.

Match the items given in Column $I$ with those in Column $II$ and select the correct option given below:

Column $I$ (Function)	Column $II$ (Part of Excretory System)
$(a)$ Ultrafiltration	$(i)$ Henle's loop
$(b)$ Concentration of urine	$(ii)$ Ureter
$(c)$ Transport of urine	$(iii)$ Urinary bladder
$(d)$ Storage of urine	$(iv)$ Malpighian corpuscle
	$(v)$ Proximal convoluted tubule

The blood leaving the kidney is significantly lower in:

Which of the following statements is/are true?
$I.$ Urine is hypertonic while entering distal convoluted tubule.
$II.$ When the urine moves in the collecting tubule,it becomes hypertonic.
$III.$ Urine is isotonic in proximal convoluted tubule.
$IV.$ Urine becomes more and more hypotonic as it passes through the descending Henle's loop.

$A$: Birds have metanephric kidneys and no urinary bladder.
$R$: South American Ostrich has a urinary bladder.