Which disorder could develop in the human body when the immune system attacks a usual harmless environmental substance

Which heredity condition causes a buildup of mucus in lungs and pancreas? a. cystic fibrosis b. heart disease c. huntington's disease d. sickle cell anemia

All ova contain sex chromosomes corresponding to: x y xx xy

Which of the following types of pollution is most responsible for large numbers of deaths worldwide because of unsafe drinking water? (a) nutrient pollution (b) thermal pollution (c) pathogen pollution (d) sediment pollution