1. The atmosphere is 80% nitrogen: why do you think plants and animals can't use
nitrogen as it is found in the atmosphere?
2. Explain what is meant by nitrogen fixation.
3. What is the role of bacteria in the nitrogen cycle?
4.Why don't legumes need nitrogen-containing fertilizers?
5.Why is nitrogen so important for living things?
6. What are the processes involved in the nitrogen cycle?
6. What are the processes involved in the nitrogen cycle?
MY ANSWERS:
1.Plants and animals cannot use nitrogen as it is found in the atmosphere as the nitrogen is in a form not usable to organisms. Plants and animals do not have the enzymes to 'fix' the nitrogen.
2.Two processes in which atmospheric or dissolved nitrogen is converted into nitrate ions; part of the nitrogen cycle; both lightning and some soil bacteria can fix nitrogen.
3.Bacteria breaks down the nitrogen into nitrates that can be consumed by plants. Although the air is made up of about 70% nitrogen, plants cannot use nitrogen in this N2 form. Nitrogen fixing bacteria change nitrogen into the form of soluble nitrates so that plants can use it. Other bacteria, known as de-nitrifying bacteria, change nitrates back into N2, which completes the nitrogen cycle.
4.Legumes "fix" nitrogen in nodules on their roots, so they do not need additional nitrogen-containing fertilizers.
5.Because proteins are required for the life process that take place in the cells of all organisms. Also nitrogen is an essential part of DNA of all organisms.
6.Nitrogen fixation, nitrogen uptake, nitrogen mineralization, nitrification, and denitrification.
