______ is the structural and functional unit of kidney.

Nephron

The correct answer is Option (4) -Nephron

The correct answer is:Nephron

The nephron is the structural and functional unit of the kidney. It is responsible for the filtration, reabsorption, and secretion processes that regulate the composition and volume of urine produced by the kidneys. Each kidney contains millions of nephrons, which consist of a renal corpuscle (composed of the glomerulus and Bowman's capsule) and a renal tubule (composed of the proximal convoluted tubule, loop of Henle, distal convoluted tubule, and collecting duct). The nephron plays a crucial role in maintaining the body's internal environment by regulating the balance of water, electrolytes, and other solutes in the blood and excreting waste products from the body.