Exploring the Nitrogen and Phosphorus Cycles

The video explores the challenges organisms face in accessing essential nutrients like nitrogen and phosphorus, despite their abundance. It explains the nitrogen cycle, highlighting the role of bacteria and plants in making nitrogen available. The phosphorus cycle is also discussed, focusing on its presence in rocks and the role of decomposers. The video concludes with a discussion on human impacts, particularly through the use of fertilizers, and the resulting ecological consequences.

What percentage of the human body is made up of nitrogen?

• 21%

• 78%

• 3%

• 1%

Which enzyme is unique to nitrogen-fixing bacteria for breaking the triple bond in nitrogen gas?

• Phosphatase

• Nitrate reductase

• Nitrogenase

• Ammonia synthase

What is the role of decomposers in the nitrogen cycle?

• They fix atmospheric nitrogen

• They convert nitrates back to nitrogen gas

• They break down organic matter to ammonia

• They consume nitrogenase

What form of nitrogen can plants directly assimilate?

• Nitrogen gas (N2)

• Nitrates (NO3)

• Nitric acid

• Nitrogenase

Which natural phenomenon can also fix atmospheric nitrogen besides bacteria?

• Volcanic eruptions

• Earthquakes

• Lightning

• Rain

What is the main reason phosphorus does not cycle through the atmosphere?

• It's too heavy

• It forms stable compounds

• It's not reactive

• It prefers the lithosphere

How long can a single phosphorus atom be caught in a biological cycle?

• 1,000 years

• 1 million years

• 100,000 years

• 10,000 years

What is the main ingredient in synthetic fertilizers that impacts the nitrogen and phosphorus cycles?

• Potassium

• Nitrogen and Phosphorus

• Calcium

• Magnesium

Who is credited with synthesizing nitrogen into ammonia for fertilizers?

• Albert Einstein

• Isaac Newton

• Fritz Haber

• Marie Curie

What is a major consequence of using synthetic fertilizers?

• Decrease in food production

• Reduction in biodiversity

• Improved soil health

• Ecosystems bombarded with nitrogen and phosphorus