Flashcard on Nitrogen and Living Organisms

Front

What is denitrification?

Back

Denitrification is the process by which nitrogen compounds in the soil are converted back into nitrogen gas (N₂), which is released into the atmosphere. This process is carried out by denitrifying bacteria.

Front

What percentage of the Earth's atmosphere is nitrogen gas (N₂)?

Back

78% of the Earth's atmosphere is nitrogen gas (N₂).

Front

What is assimilation in the context of nitrogen?

Back

Assimilation is the process by which plants and other organisms incorporate nitrogen from inorganic sources into organic molecules, such as amino acids and proteins.

Front

Which organisms are primarily responsible for nitrogen fixation?

Back

Nitrogen-fixing bacteria, such as Rhizobium, are primarily responsible for nitrogen fixation, which occurs in the root nodules of certain plants.

Front

What role do nitrogen-fixing bacteria play in the nitrogen cycle?

Back

Nitrogen-fixing bacteria convert atmospheric nitrogen (N₂) into ammonia (NH₃), which can then be used by plants to synthesize organic compounds.

Front

What is nitrification?

Back

Nitrification is the biological process in which ammonia (NH₃) is oxidized to nitrites (NO₂⁻) and then to nitrates (NO₃⁻) by nitrifying bacteria.

Front

What is the significance of nitrogen in living organisms?

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Nitrogen is a crucial element for all living organisms as it is a key component of amino acids, proteins, and nucleic acids (DNA and RNA).

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What is the process of nitrogen fixation?

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Nitrogen fixation is the conversion of atmospheric nitrogen (N₂) into ammonia (NH₃) or related compounds, making nitrogen available to living organisms.

Front

How do plants obtain nitrogen?

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Plants obtain nitrogen primarily through the uptake of nitrates (NO₃⁻) and ammonium (NH₄⁺) from the soil.

Front

What is the role of decomposers in the nitrogen cycle?

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Decomposers break down organic matter, releasing nitrogen back into the soil in the form of ammonia, which can then be converted into nitrates by nitrifying bacteria.