Question

1. ccc systems what are the two roles of bacteria in the nitrogen cycle? 2. sep construct explanations how does water get up to the atmosphere, and how does it get back down to earths surface?

Explanation:

1. In the nitrogen cycle, bacteria have two main roles. First, nitrogen - fixing bacteria convert atmospheric nitrogen (\(N_2\)) into ammonia (\(NH_3\)) which plants can use. Second, denitrifying bacteria convert nitrates (\(NO_3^-\)) back into nitrogen gas (\(N_2\)) to return it to the atmosphere.
2. Water gets up to the atmosphere through processes like evaporation (from bodies of water) and transpiration (from plants). Once in the atmosphere, water vapor condenses to form clouds. Then, through precipitation (such as rain, snow, sleet, or hail), water gets back down to Earth's surface.

Answer:

1. Nitrogen - fixing bacteria convert \(N_2\) to \(NH_3\); denitrifying bacteria convert \(NO_3^-\) to \(N_2\).
2. Evaporation/transpiration takes water to the atmosphere; precipitation brings it back.