Which of the following organs is not present in a pair in the human body?

Which one of the following correctly explains the function of a specific part of the human nephron?

Arrange the following parts of the nephron in a sequential manner and select the correct option accordingly.
$I.$ Glomerulus
$II.$ Bowman's capsule
$III.$ Henle's loop
$IV.$ Proximal convoluted tubule $(PCT)$
$V.$ Collecting duct
$VI.$ Distal convoluted tubule $(DCT)$

Which of the following is not a part of the nephron?

In a rabbit,the urinary bladder opens into:

State the location and function of podocyte.