Question

Number of nephrons of a kidney is equal to
(A) Sum of Bowman’s capsule and glomerulus
(B) Sum of Bowman’s capsule and Malpighian corpuscles
(C) Double the number of Bowman’s capsule
(D) Equal to number of Bowman’s capsule

Answer 1

Hint: Nephrons are differentiated into regions – renal corpuscle and renal tubule. Renal corpuscle consists of Bowman’s capsule and glomerulus.

Complete step by step answer:
Human excretory system consists of a pair of kidneys. Nephrons are considered as the structural and functional unit of kidneys. Each kidney approximately consists of 2, 00,000 to 18,00,000 of nephrons.
Each nephron consists of two regions – renal corpuscle and renal tubule. The Renal corpuscle or Malpighian body consists of Bowman’s capsule which is a cup-shaped structure. Within Bowman’s capsule, tufts of capillaries are present which is known as glomerulus. Tufts of capillaries are formed due to afferent arteriole which is a fine branch of renal artery.
Renal tubule comprises proximal convoluted tubule (PCT), Henle’s loop (Ascending and Descending), and distal convoluted tubule (DCT). The distal convoluted tubule of millions of nephrons come together to open into collecting duct.
Since, each nephron consists of Bowman’s capsule, glomerulus, PCT, Henle’s loop and DCT, counting any of these parts, will help in estimating the amount of nephrons present in kidneys.

Hence the correct answer is option(D)

Note: Remembering the parts of nephrons is essential when answering these types of questions. Important point to be noted is that collecting duct is not a part of a single nephron. Group of nephrons open into a single duct known as a collecting duct.