Medical Definition of Red blood cells. Red blood cells: The blood cells that carry oxygen. Red cells contain hemoglobin and it is the hemoglobin which permits them to transport oxygen (and carbon dioxide). Hemoglobin, aside from being a transport molecule, is a pigment. It gives the cells their red color (and their name).
Alexander Milne Calder (August 23, 1846 â June 4, 1923) was a Scottish American sculptor best known for the architectural sculpture of Philadelphia City Hall. Both his son, Alexander Stirling Calder, and grandson, Alexander Sandy Calder, became significant sculptors in the 20th century.
Alexander the Great (356 BC to 323 BC) was the King of Macedonia. He conquered most of the known world through vigorous military campaigns. He was never defeated in battle. He was born in Paella, Macedonia, in July 356 BC. His educator was the great Greek philosopher  Aristotle.