Answer: 100-120 days
Notes: Red blood cells (RBCs) have an average lifespan of 100-120 days and are produced in the bone marrow, while the spleen is where they are broken down. Macrophages break down RBCs into globin and heme, recycling amino acids and iron for various purposes, including protein synthesis. Some parts of old RBCs are reused in creating new ones. The average lifespan of cells in the human body is 7 to 10 years, but it varies across cell types and organs. Neutrophil cells, for example, last about two days.
