Nitrogen Cycle Basics
What is the most abundant form of nitrogen in the atmosphere?
What is nitrogen gas (N₂)?
What is the conversion of ammonia to nitrites and then nitrates called?
What is nitrification?
How do humans add excess nitrogen to the environment?
What is through the use of chemical fertilizers and fossil fuel combustion?
What is the relationship between legumes and nitrogen-fixing bacteria?
What is a symbiotic relationship?
True or False: Plants can directly absorb nitrogen gas (N₂) from the atmosphere.
What is false?
Which process involves converting nitrogen gas into a form plants can absorb?
What is nitrogen fixation?
What role do decomposers play in the nitrogen cycle?
What is breaking down organic matter into ammonia?
What environmental issue can result from nitrogen runoff into water bodies?
What is eutrophication?
Which enzyme is used by nitrogen-fixing bacteria to convert nitrogen gas into ammonia?
What is nitrogenase?
What percentage of the Earth's atmosphere is nitrogen?
What is 78%?
Name the organisms primarily responsible for nitrogen fixation.
What are nitrogen-fixing bacteria, such as Azotobacter or Rhizobium?
What happens to nitrogen during assimilation?
What is the absorption of nitrates and ammonium by plants to form proteins and DNA?
What is the term for nitrogen compounds contributing to air pollution and climate change?
What are nitrogen oxides (NOₓ)?
How does nitrogen fixation differ in free-living bacteria compared to symbiotic bacteria?
Free-living bacteria fix nitrogen independently, while symbiotic bacteria require a host plant.
What do we call plants like beans and peas that have nitrogen-fixing bacteria in their roots?
What are legumes?
What is the process by which dead plants and animals are broken down, returning nitrogen to the soil as ammonia?
What is ammonification?
In which natural phenomenon does lightning play a role in nitrogen fixation?
What is atmospheric nitrogen fixation?
How does excess nitrogen in the soil affect groundwater?
What is nitrate contamination, which can make water unsafe to drink?
Why is nitrogen considered a limiting nutrient in ecosystems?
Because its availability controls the growth of organisms and ecosystems rely on the nitrogen cycle to replenish it.
True or False: Lightning can naturally fix nitrogen into a usable form for plants.
What is true?
Which step in the nitrogen cycle releases nitrogen back into the atmosphere?
What is denitrification?
Which chemical compound is primarily formed during nitrogen fixation in the soil?
What is ammonia (NH₃)?
What is one way humans can reduce nitrogen pollution in agricultural practices?
What is crop rotation or using cover crops to reduce the need for synthetic fertilizers?
Explain how nitrogen is essential in the formation of DNA.
Nitrogen is a key element in nitrogenous bases, which are the building blocks of DNA and RNA.
Which part of the nitrogen cycle balances the nitrogen input and output in ecosystems?
What is denitrification?