Carbon Cycle and Its Processes

The video explains the carbon cycle, highlighting the constant percentage of carbon dioxide in the atmosphere. It covers photosynthesis, where plants absorb carbon dioxide to produce food, and how this carbon flows through the food chain. The video also discusses the role of respiration and combustion in returning carbon dioxide to the atmosphere. Additionally, it addresses the conversion of carbon in extinct animals into fossil fuels, maintaining the carbon balance.

What is the constant percentage of carbon dioxide in the Earth's atmosphere?

• 30%

• 3%

• 0.3%

• 0.03%

During photosynthesis, what do plants primarily use carbon dioxide for?

• To create energy

• To manufacture food

• To produce oxygen

• To absorb sunlight

How does carbon flow through the food chain?

• Through food

• Through water

• Through air

• Through soil

What happens to carbon in food during respiration?

• It is used for growth

• It is stored as fat

• It is oxidized to form carbon dioxide

• It is converted to oxygen

What role do microorganisms play in the carbon cycle?

• They produce carbon dioxide

• They break down dead matter

• They absorb carbon dioxide

• They create fossil fuels

What is the main constituent of protein molecules used in body structures?

• Oxygen

• Carbon

• Nitrogen

• Hydrogen

What is the process called when fossil fuels are burned to release carbon dioxide?

• Photosynthesis

• Respiration

• Combustion

• Oxidation

How do trees contribute to the carbon cycle?

• By producing fossil fuels

• By taking up carbon dioxide

• By releasing nitrogen

• By absorbing oxygen

What happens to carbon in extinct animals that is not consumed by microorganisms?

• It turns into oxygen

• It is converted into fossil fuels

• It becomes part of the soil

• It is lost forever

What ensures the constant percentage of carbon dioxide in the atmosphere?

• Photosynthesis alone

• Respiration alone

• Combustion alone

• The entire carbon cycle