Carbon Cycle LSF

Carbon is described as a very versatile element because its electron structure allows it to make lots of different molecules. Where can carbon be found on Earth?

• Only in the atmosphere as CO2​.
• In rocks, oceans, and the atmosphere.
• Only in living things on Earth.
• Only in fossil fuels.

Answer explanation

Carbon can be found in rocks, oceans, and the atmosphere.

The carbon cycle involves the repeated cycling of carbon atoms between the Earth and the atmosphere. By what means does carbon move from one storage reservoir to another?

• Primarily through volcanic eruptions.
• Through combustion only.
• Through a variety of mechanisms.
• Exclusively through photosynthesis and respiration.

Answer explanation

Carbon moves through a variety of mechanisms.

In which form is carbon typically found when stored in the atmosphere?

• As methane (CH₄​).

• Dissolved in water.
• As CO2​.

• As fossil fuels.

Answer explanation

Carbon is stored in the Atmosphere as CO2​.

How is carbon primarily stored in the Geosphere, according to the sources?

• As CO2​.
• As Producers.
• As fossil fuels.
• Dissolved in water.

Answer explanation

Carbon is stored in the Geosphere as fossil fuels.

In the context of the carbon cycle, which process removes carbon dioxide (CO2​) from the atmosphere and stores it in producers?

• Respiration.
• Combustion.
• Decomposition.
• Photosynthesis.

Answer explanation

Carbon dioxide is absorbed by producers to make carbohydrates in photosynthesis.

Which process releases carbon dioxide (CO2​) into the atmosphere from living things, such as animals and plants?

• Dissolution.
• Erosion.
• Respiration.
• Sedimentation.

Answer explanation

Carbon is released into the atmosphere during respiration.

In Stage One of a simplified carbon cycle, carbon enters the atmosphere as carbon dioxide through which two main biological and chemical processes?

• Photosynthesis and dissolution.
• Respiration and combustion.
• Decomposition and sedimentation.
• Geological activity and human influence.

Answer explanation

Carbon enters the atmosphere as carbon dioxide from respiration and combustion (Stage One).

When dead organisms are decomposed by bacteria and fungi, the carbon in their bodies is typically returned to the atmosphere as carbon dioxide. Under what conditions is this decomposition prevented, leading to fossilisation?

• When there is excess water present.
• When there is heat, pressure and time.
• When temperatures are high.
• When oxygen levels are high.

Answer explanation

Fossilisation takes place deep underground when there is heat and pressure for. along time and when decomposition is prevented.

What process directly moves carbon from the ocean (hydrosphere) to deep underground sediments?

• Dissolution.
• Erosion.
• Sedimentation.
• Respiration.

Answer explanation

Sedimentation moving material down into marine deposits.

Carbon dioxide in the atmosphere is used in photosynthesis to produce what?

• Water and oxygen.
• Carbohydrates (like glucose)
• Methane.
• Fossil fuels.

Answer explanation

Carbon dioxide is used in photosynthesis to produce carbohydrates.