10th test 1 biology essays

Question 1

nitrogen cycle essay

Answer 1

1. nitrogen in the atmosphere
2. lightning moves the nitrogen and legumes extract it from the air
3. nitrogen-fixing bacteria grows on the legumes roots and change the atmospheric nitrogen to nitrates
4. the plants may die and when they decay, the nitrates become nitrifying bacteria in the soil
5. denitrifying bacteria converts the nitrates into atmospheric nitrogen
6. plants with nitrogen-fixing bacteria could be eaten by humans or animals in the form of protein