Carbon and Nitrogen Cycle

What is the primary source of carbon in the carbon cycle?

• Nitrogen (N2)

• Oxygen (O2)

• Methane (CH4)

• Carbon dioxide (CO2)

Name the process by which plants take in carbon dioxide and water and convert it to glucose

• Photosynthesis

• Combustion

• Respiration

• Decomposition

What role do decomposers play in the carbon cycle?

• Decomposers break down dead organic matter and release carbon dioxide back into the atmosphere.

• Decomposers have no impact on the carbon cycle

• Decomposers convert carbon dioxide into oxygen

• Decomposers absorb carbon dioxide from the atmosphere

Which process releases carbon dioxide back into the atmosphere?

• Photosynthesis

• Burning fossil fuels

• Nitrogen fixation

• Respiration

What is denitrification in the nitrogen cycle?

• Denitrification is the process of converting nitrogen gas into nitrates by plants.

• Denitrification is the conversion of nitrates into nitrogen gas by soil bacteria.

• Denitrification is the transformation of nitrates into ammonia by fungi.

• Denitrification is the absorption of nitrogen gas by water bodies.

How do nitrogen-fixing bacteria contribute to the nitrogen cycle?

• Nitrogen-fixing bacteria convert nitrogen into a form that is toxic to plants

• Nitrogen-fixing bacteria release excess nitrogen into the atmosphere

• Nitrogen-fixing bacteria convert atmospheric nitrogen into a form that plants can use.

• Nitrogen-fixing bacteria contribute to the depletion of nitrogen in the soil

Explain the role of nitrifying bacteria in the nitrogen cycle.

• Nitrifying bacteria convert ammonia into nitrites and then into nitrates.

• Nitrifying bacteria convert nitrates into carbon dioxide.

• Nitrifying bacteria convert nitrites into ammonia.

• Nitrifying bacteria convert ammonia into phosphates.

What happens to nitrogen compounds when decomposers break down organic matter?

• Nitrogen compounds are converted into sulfur and oxygen.

• Nitrogen compounds are converted into phosphorus and potassium.

• Nitrogen compounds are converted into carbon dioxide and water.

• Nitrogen compounds are converted into ammonium, nitrites, and nitrates.

How do decomposers help in recycling nutrients in the ecosystem?

• Decomposers break down dead organic matter, releasing nutrients back into the soil.

• Decomposers increase the toxicity of the soil

• Decomposers reduce the nutrient content in the ecosystem

• Decomposers absorb nutrients from the soil

Why are carbon and nitrogen cycles essential for maintaining life on Earth?

• Carbon and nitrogen cycles deplete essential elements needed for life

• Carbon and nitrogen cycles have no impact on living organisms

• Carbon and nitrogen cycles are harmful to the environment

• Carbon and nitrogen cycles regulate the availability of crucial elements for living organisms, such as carbon for photosynthesis and organic molecules, and nitrogen for proteins and nucleic acids.