Activity 9: Biology to Go

1. Nitrogen is needed to make protein and also deoxyribonucleic acid (DNA).

2. Plants are helped by the nitrogen-fixing bacteria that are found in root nodules or in the soil. These bacteria change the atmospheric nitrogen into nitrates that are then absorbed by the roots of the plants. Lightning also helps because it changes the nitrogen gas into nitrates that get to the soil after they are dissolved in the rain. These nitrates are also absorbed by the roots of the plants.

3. The animals eat the plants and get the nitrogen from them.

4. Aerating the lawn deprives the anaerobic bacteria (denitrifying bacteria) to change the nitrates into nitrites. Nitrates will then remain in the soil and can be used by the grass to make proteins.

5. Phosphorous is a necessary element in DNA, in many molecules found in living cells, and in the bones of vertebrates.

6. a) An increase in wheat yield will occur. b) The fertilizers with their nitrogen and phosphates will eventually go into streams and lakes where they may cause algal bloom resulting in the depletion of oxygen supply causing the death of other species. The death of the other species exacerbates the problem because as the decomposers act on them, more oxygen is used, making it more unavailable to the other organisms.