They will avoid areas where DO levels are below 3 mg/L, but generally do not begin to suffer fatalities due to oxygen depletion until levels fall below 2 mg/L 22. The mean DO levels should remain near 5.5 mg/L for optimum growth and survival Â¹Â².n a stable body of water with no stratification, dissolved oxygen will remain at 100% air saturation. 100% air saturation means that the water is holding as many dissolved gas molecules as it can in equilibrium.
1 Most protist diseases in humans are caused by protozoa. 2  Protozoa make humans sick when they become human parasites. 3  Trypanosoma protozoa cause Chagas disease and sleeping sickness. 4  Giardia protozoa cause giardiasis, and Plasmodium protozoa cause malaria.esson Summary. 1  Most protist diseases in humans are caused by protozoa. 2  Protozoa make humans sick when they become human parasites. 3  Trypanosoma protozoa cause Chagas disease and sleeping sickness. 4  Giardia protozoa cause giardiasis, and Plasmodium protozoa cause malaria.
1 2 diseases that are common. 2  2 diseases that are uncommon. 3  1 disease that is rare. 4  7 diseases that are very rare. 5  389 diseases without any prevalence information. 6  The following drugs, medications, substances or toxins may possibly cause Birth defects as a side effect.he following causes of Birth defects are diseases or medical conditions that affect more than 10 million people in the USA: 1  Diabetes-birth defects. 2  Genetic defect. 3  Obesity. 4  Toxoplasmosis.