What is the independent variable? 9. What is the dependent variable? (What will we measure?) Play the video to get the results and answer these questions: 10. What is the DO level of the bottle that was in the light? mg/L 11. What is the DO level of the bottle that was in the dark? mg/L Fill in this chart: Initial Dissolved Oxygen (ppm) (both bottles) Final Dissolved Oxygen in Dark Bottle (no photosynthesis, only respiration) Final Dissolved Oxygen in Light Bottle (both respiration and photosynthesis)

me two

explanation:

because i hate it

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.