How is protozoa useful to humans?

What organ function is propulsion? What happens to the refractive index when temperature increases? Explain how the first plant cell could have evolved with the help of bacteria? What rocks are volcanoes made up of? What kind of lighting would you use to create very distinct shadows? What does producer means? What does the earth's revolution control what does the earth's revolution control? What molecular basis of heredity is? What are the other names for the rows and columns in the periodic table? What population groups should have genetic testing? Which geologic process forms new crust on the ocean floor? Can a cyclotron accelerate negative ions? Where is 19 north and 100 west? What is Keq for the reaction N2 plus 3H2 2NH if the equilibrium concentrations are NH3 3 m N2 1 m and H22m? Is heat an organism? What erupted in may of 1902? Why is it warm in places near the equator like the Philippines? How many carbons are in 3C6H1206? What type of intermolecular forces are dominant in octane? Which type of energy is being converted into kinetic energy as a marble falls from a shelf?

How is protozoa useful to humans?