Cellular organelles perform specialized functions in the body. Red blood cells, or RBCs, transport oxygen to the tissues in the body. New RBCs are only produced in the bone marrow, while mature RBCs that travel throughout the body are continuously recycled until they wear out. This means that mature RBCs do not undergo DNA replication and cell division. Which organelle would be missing in a mature red blood cell? a. cytoplasm b. microtubules c. cell membrane d. nucleus