Understanding the Carbon Cycle

Why is carbon essential for plants to produce their own food?

• It provides energy directly from the sun.

• It is a component of water.

• It is needed for photosynthesis.

• It is a source of oxygen.

What percentage of the human body is made up of carbon by weight?

• 18%

• 30%

• 25%

• 10%

Which of the following is NOT a carbon source?

• Combustion of fossil fuels

• Photosynthesis

• Respiration of animals

• Volcanic eruptions

What is a carbon sink?

• A greenhouse gas

• A process that absorbs carbon from the atmosphere

• A process that releases carbon into the atmosphere

• A type of fossil fuel

Which of the following is an example of a carbon reservoir?

• Photosynthesis

• Respiration

• The Earth's atmosphere

• Combustion

How do oceans contribute to the carbon cycle?

• They only absorb carbon from the atmosphere.

• They do not interact with carbon.

• They absorb carbon in cold regions and release it in warm regions.

• They only release carbon into the atmosphere.

What happens to carbon when plants, animals, or humans die?

• It is released into the atmosphere immediately.

• It is absorbed by the oceans.

• It is transferred to the Earth and can become fossil fuels over time.

• It disappears completely.

What is the role of photosynthesis in the carbon cycle?

• It releases carbon dioxide into the atmosphere.

• It breaks down carbon dioxide into usable compounds for plants.

• It converts carbon into fossil fuels.

• It absorbs oxygen from the atmosphere.

What is the impact of an imbalance between carbon sources and sinks?

• It has no significant impact on the environment.

• It results in global warming due to excess carbon release.

• It causes an increase in carbon absorption.

• It leads to a decrease in global temperatures.

What can be done to increase carbon absorption and reduce global warming?

• Burn more fossil fuels

• Plant more trees

• Increase deforestation

• Reduce photosynthesis