Earth Cycles The Nitrogen Cycle: Of microbes and men by John Arthur Harrison, Ph.D. Reading Quiz Teach with this 1. What is the most common way that nitrogen fixation occurs? lightning nitrogen fixing bacteria fossil fuel combustion forest fires 2. Atmospheric nitrogen (N2 gas) is easily taken up and used by plants and animals. true false 3. Organic nitrogen is coverted back to inorganic nitrogen like ammonium through the process of nitrogen fixation nitrification decay none of the choices 4. Eutrophication in coastal waters can cause an increase in respiratory diseases in fish agricultural productivity harmful algal blooms denitrification 5. Ammonium (NH4) stays in soil, while nitrate (NO3) is easily leached out. Why do they behave so differently? NO3 is broken down by bacteria, so it is easily carried away NH4has a positive charge and sticks to soil particles. NH4 is unavailable to organisms, so it remains unchanged in the soil. NO3 is only produced when water is flowing through soil. 6. Which process releases dinitrogen gas (N2) back into the atmosphere? denitrification nitrogen fixation decay nitrification 7. Once bacteria have fixed nitrogen, it can be taken up by plants and animals, where it is used in the production of nitrogen oxides carbohydrates proteins energy 8. Synthetic fertilizers add _____________ to the soil. organic nitrogen fixed nitrogen (ammonium) nitrogen oxides Rhizobium bacteria 9. Legumes host nitrogen fixing bacteria, and thus are good crops to plant to replenish the soil. true false 10. Which of the following is a component of acid rain? ammonium denitrifying bacteria nitrogen oxides organic nitrogen Score Quiz
