Amoeba is a microscopic, single-celled organism that feeds using a process called phagocytosis. When it senses food, it extends finger-like projections called pseudopodia around the food particle. These pseudopodia engulf the food, forming a food vacuole inside its body. Digestive juices are then secreted into this food vacuole, breaking down the food into simpler substances. The digested food is absorbed and used for growth and maintenance, while undigested waste is expelled from the cell.