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.
Lesson 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.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.
Pathogenic diseases are caused by what is called a pathogen. Pathogens are parasitic organisms that cause disease int heir host. There are five different groups of pathogens: â¦ Viruses, bacteria, fungi, protozoans and parasitic worms. Deficiency diseases are just as the name suggests. physiological disease is caused when the normal or proper working of the body is affected because the body's organs have malfunctioned or it's cellular structures have chang â¦ ed over a period of time causing illness. Therefore most diseases you can name fall under the physiological category.