ET Carbon cycle 4/26/23

Which of these is a real path in the carbon cycle?

• Atmospheric CO₂ -> land plants -> limestone
• Atmospheric CO₂ -> oceanic CO₂ -> marine plants/algae -> coal
• Atmospheric CO₂ -> land plants -> land animals -> soil

Which of the following add carbon dioxide to the atmosphere?

• volcanoes
• combustion of fossil fuels
• animal and plant respiration
• all of these

Organisms that do not decompose can be buried and become what?

• water
• nutrients
• air
• fossil fuels

Respiration is the process by which animals take in _____ and release _____. 

• photosynthesis, air
• carbon, oxygen
• oxygen
• oxygen, carbon dioxide

The average temperature of the surface of Earth has increased approximately 1°C in the past century. Which reason best explains this increase in temperature?

• lower levels of ozone in the atmosphere
• lower levels of nitrogen in the atmosphere
• higher levels of carbon dioxide and other greenhouse gases in the atmosphere
• higher levels of oxygen in the atmosphere

The diagram shows the flow of organic molecules through an ecosystem. What process is identified by the label Y?

• Combustion

• Decomposition

• Photosynthesis

• Cellular Respiration