Nutrient Cycles: Carbon, Water, And Nitrogen Explained

This video covers the nutrient cycles in IGCSE biology, focusing on the carbon, water, and nitrogen cycles. It explains how carbon dioxide is released and absorbed in the carbon cycle, the stages of the water cycle including precipitation and evaporation, and the complex processes of the nitrogen cycle involving nitrogen-fixing and denitrifying bacteria. The video concludes with a call to action for viewers to like and subscribe.

What is one major source of carbon dioxide in the atmosphere?

• Photosynthesis

• Combustion of fossil fuels

• Nitrogen fixation

• Transpiration

How do plants primarily absorb carbon dioxide?

• Through nitrogen fixation

• Via transpiration

• By photosynthesis

• Through their roots

What is the term used for rain in the water cycle?

• Transpiration

• Evaporation

• Condensation

• Precipitation

What process describes water seeping into the soil?

• Condensation

• Percolation

• Evaporation

• Transpiration

Why can't plants directly use nitrogen gas from the atmosphere?

• It is too reactive

• It is unreactive

• It is toxic

• It is too heavy

What natural phenomenon helps convert nitrogen gas into nitrogen oxides?

• Wind

• Lightning

• Sunlight

• Rain

What do nitrogen-fixing bacteria convert nitrogen gas into?

• Ammonium compounds

• Nitrates

• Carbon dioxide

• Nitrogen oxides

What role do nitrifying bacteria play in the nitrogen cycle?

• Convert nitrogen oxides into nitrogen gas

• Convert nitrates into nitrogen gas

• Convert ammonium into nitrates

• Convert nitrogen gas into ammonium

What is the function of denitrifying bacteria?

• Convert nitrogen gas into ammonium

• Convert nitrates into nitrogen gas

• Convert ammonium into nitrates

• Convert nitrogen oxides into ammonium

How is nitrogen returned to the atmosphere in the nitrogen cycle?

• Through photosynthesis

• By denitrifying bacteria

• Through percolation

• Via transpiration