what is the typical lifespan of a leukocyte? question 20 options: because all leukocytes are unable to undergo mitosis (cell division), their lifespan is usually only a few seconds. the lifespan of a leukocyte is approximately 120-150 days. the lifespan of a leukocyte typically is measured only in hours or days. the lifespan of a leukocyte is extremely variable, measuring in hours to years or decades. many leukocytes can live indefinitely if they are in well-protected locations.