El ciclo del nitrógeno

The video explains the nitrogen cycle, highlighting how nitrogen is essential for life but cannot be used directly by plants and animals. It describes the conversion of nitrogen gas into usable compounds by nitrogen-fixing bacteria in the soil and legumes. Plants absorb these nitrates to make proteins, which are then passed through the food chain. Decomposition returns nitrogen to the soil, where bacteria convert it into ammonium ions and then back into nitrates. Finally, denitrifying bacteria transform nitrates into nitrogen gas, completing the cycle.

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

• They consume nitrogen from the air.

• They transform nitrates into nitrogen gas.

• They decompose dead matter.

• They convert nitrogen gas into nitrates.

How do animals obtain nitrogen?

• By consuming plants.

• By absorbing it from the air.

• By direct absorption from the soil.

• By drinking water.

What is the role of decomposers in the nitrogen cycle?

• They convert ammonium ions into nitrates.

• They fix nitrogen in the soil.

• They transform nitrates into nitrogen gas.

• They break down proteins and waste into ammonium ions.

What happens to nitrates in waterlogged soils?

• They are used by animals directly.

• They are absorbed by plants.

• They are converted into nitrogen gas.

• They are transformed into ammonium ions.

Why is the nitrogen cycle important for life on Earth?

• It creates new elements.

• It recycles nitrogen into usable forms for living organisms.

• It provides oxygen for breathing.

• It removes carbon dioxide from the atmosphere.