The Nitrogen Cycle and Its Importance

What is the primary form of nitrogen found in the atmosphere?

Which process converts atmospheric nitrogen into a form usable by plants?

• Denitrification

• Nitrogen fixation

• Ammonification

• Nitrification

Which microorganisms are primarily responsible for nitrogen fixation in the soil?

• Fungi

• Viruses

• Bacteria

• Algae

What is the role of nitrifying bacteria in the nitrogen cycle?

• Convert ammonia into nitrites and nitrates

• Convert nitrates into nitrogen gas

• Fix atmospheric nitrogen

• Decompose organic matter

Which of the following is a natural source of nitrogen on Earth?

• Volcanic eruptions

• Photosynthesis

• Ocean evaporation

• Rock weathering

What is the significance of the nitrogen cycle for living organisms?

• It provides oxygen for respiration.

• It supplies essential nutrients for DNA and proteins.

• It regulates Earth's temperature.

• It controls water distribution.

Which process in the nitrogen cycle involves the conversion of nitrates back into nitrogen gas?

• Nitrogen fixation

• Nitrification

• Denitrification

• Ammonification

How do plants primarily obtain nitrogen?

• Absorbing nitrogen gas directly from the atmosphere

• Through photosynthesis

• Absorbing nitrates and ammonium from the soil

• Consuming other plants

Which of the following is a human activity that significantly impacts the nitrogen cycle?

• Deforestation

• Industrial agriculture

• Urbanization

• Mining

What is the process called when organic nitrogen is converted into ammonia?

• Nitrification

• Ammonification

• Denitrification

• Nitrogen fixation