Carbon Cycle Quiz

What is the process called where nitrogen gas in the air is converted into a form that plants can use?

• Photosynthesis

• Nitrogen fixation

• Respiration

• Transpiration

What is the role of plants in the nitrogen cycle?

• They release nitrogen gas into the air.

• They convert nitrogen gas into a usable form.

• They absorb nitrogen from the soil.

• They produce nitrogen gas.

Which of the following is the first step in the nitrogen cycle?

• Free nitrogen is found in the atmosphere

• Decomposers return nitrates to the soil

• Nitrates are absorbed by plants

• Animal dies

What process returns nitrates to the soil in the nitrogen cycle?

• Free nitrogen is found in the atmosphere

• Decomposers return nitrates to the soil

• Nitrates are absorbed by plants

• Animal dies

Which of the following statements is true about the nitrogen cycle?

• Free nitrogen is fixed by nitrogen-fixing bacteria in the soil

• Nitrates are absorbed by animals

• Free nitrogen is found in the soil

• Plants return nitrates to the atmosphere

What happens to nitrates in the soil during the nitrogen cycle?

• They are absorbed by plants

• They are converted into free nitrogen by decomposers

• They are released into the atmosphere

• They are eaten by animals

In the nitrogen cycle, what happens after an animal dies?

• Nitrates are absorbed by plants

• Decomposers return nitrates to the soil

• Free nitrogen is found in the atmosphere

• Animal is eaten by a bigger animal

What is the role of nitrogen-fixing bacteria in the nitrogen cycle?

• They convert free nitrogen into nitrates

• They return nitrates to the soil

• They absorb nitrates from the soil

• They release nitrogen into the atmosphere

What happens to a plant in the nitrogen cycle?

• It is eaten by an animal

• It absorbs free nitrogen from the atmosphere

• It releases nitrates into the soil

• It fixes nitrogen in the soil

What is the final step in the nitrogen cycle as described in the document?

• Animal is eaten by a bigger animal

• Nitrates are absorbed by plants

• Free nitrogen is found in the atmosphere

• Decomposers return nitrates to the soil