Mitosis: Why do chemotherapy drugs, given to fight cancer, cause a person’s hair to fall out?

• Level 1: “I know that the drugs do this, but I don't have the slightest idea why. There is probably a simple explanation that I am overlooking.” (4%)
• Level 2: (minimal accurate prior knowledge) “I think it is because the drugs are trying to kill all of the bad cells and hair is dead cells, so the drugs just see hair as bad cells and gets rid of them.” (30%)
• Level 3: (moderate accurate prior knowledge) “The chemotherapy drugs used to fight cancer attempt to kill off the living cancer cells. Hair cells are not nearly as hard to kill as cancer cells and this results in the killing off of many cells with the ultimate goal of killing the cancer cells.” (44%)
• Level 4: (answers correctly and completely) “Chemotherapy poisons all body cells to some extent, but particularly rapidly dividing cells undergoing mitosis such as cancer cells. It also affects other rapidly dividing cells (hair follicles, cells lining the stomach, and red blood cells) which causes some of the common side effects.” (22%)

  n= 169, Biology N100, Spring 2002

  More about Warm Up responses and analysis can be found in Marrs, Blake and Gavrin, Journal of College Science Teaching, September 2003