वृक्क (Kidney) की कार्यात्मक इकाई क्या है?

उत्तर: (B) नेफ्रॉन — Nephron (नेफ्रॉन) is the functional unit of kidney — each kidney has about 1 million nephrons. They filter blood and produce urine. Neuron is for nervous system, Alveoli for lungs, Villi for intestine...