Nitrogen Cycle

The video explains the nitrogen cycle, highlighting its importance for living organisms. It covers the four main processes: nitrogen fixation, decay, nitrification, and denitrification. Nitrogen fixation is detailed with biological, atmospheric, and industrial methods. The cycle continues with nitrification, where ammonia is converted to nitrates, and denitrification, which returns nitrogen to the atmosphere, completing the cycle.

What percentage of the Earth's atmosphere is composed of nitrogen?

• 100%

• 50%

• 79%

• 21%

Which of the following is NOT a process involved in nitrogen fixation?

• Biological fixation

• Atmospheric fixation

• Photosynthesis

• Industrial fixation

What role do decomposers play in the nitrogen cycle?

• They fix nitrogen in the soil.

• They release nitrogen gas back into the atmosphere.

• They break down animal waste and dead matter into ammonia.

• They convert nitrogen gas into nitrates.

During nitrification, ammonia is converted into what compound?

• Nitrites

• Ammonium

• Nitrates

• Nitrogen gas

What is the final step in the nitrogen cycle that replenishes the atmosphere with nitrogen gas?

• Denitrification

• Nitrogen fixation

• Nitrification

• Decay