Question

1. which of the following is the correct sequence of events in the nitrogen cycle? a. ammonium → nitrate → nitrite b. nitrate → nitrite → ammonium c. ammonium → nitrite → nitrate 11. what type of bacteria live in the soil or root nodules of legumes and convert nitrogen gas into ammonium or other organic nitrogen compounds? a. nitrifying bacteria b. nitrogen - fixing bacteria c. denitrifying bacteria 12. in what type of environment does denitrification typically take place? a. oxygen - depleted environments like wetlands and soil with poor drainage b. oxygen - rich environments like mountain tops and rainforest canopies c. carbon - dioxide rich environments like wetlands and deserts. short answer 13. describe the sequence of events that occurs when a nitrogen gas atom in an animals dna cycles through in the nitrogen cycle to eventually become an atom of atmospheric nitrogen.

Explanation:

1. In the nitrogen - cycle, ammonium is first converted to nitrite by ammonia - oxidizing bacteria, and then nitrite is converted to nitrate by nitrite - oxidizing bacteria. So the sequence is ammonium → nitrite → nitrate.
2. Nitrogen - fixing bacteria live in the soil or root nodules of legumes and convert nitrogen gas into ammonium or other organic nitrogen compounds.
3. Denitrification is an anaerobic process and typically takes place in oxygen - depleted environments like wetlands and soil with poor drainage.
4. When a nitrogen gas atom in an animal's DNA cycles through the nitrogen cycle to become an atmospheric nitrogen atom: First, the animal dies and decomposes. The organic nitrogen in its DNA is converted to ammonium by decomposers. Then, ammonium is converted to nitrite and then to nitrate by nitrifying bacteria. Finally, denitrifying bacteria convert nitrate to nitrogen gas, which returns to the atmosphere.

Answer:

1. c. ammonium → nitrite → nitrate
2. b. nitrogen - fixing bacteria
3. a. oxygen - depleted environments like wetlands and soil with poor drainage
4. The animal dies and decomposes, organic nitrogen in DNA is converted to ammonium by decomposers, ammonium is converted to nitrite and then nitrate by nitrifying bacteria, and denitrifying bacteria convert nitrate to nitrogen gas which returns to the atmosphere.