Exploring Biogeochemical Cycles

What is the primary source of evaporation in the water cycle?

• Oceans

• Lakes

• Rivers

• Mountains

What process purifies water from the ocean during the water cycle?

• Transpiration

• Evaporation

• Precipitation

• Condensation

Which biogeochemical cycle involves the process of transpiration?

• Phosphorus cycle

• Carbon cycle

• Nitrogen cycle

• Water cycle

Which process in the carbon cycle involves the release of carbon dioxide by animals?

• Decomposition

• Photosynthesis

• Combustion

• Respiration

What is the role of green plants in the carbon cycle?

• They absorb carbon dioxide

• They decompose organic matter

• They produce fossil fuels

• They release carbon dioxide

What percentage of the atmosphere is made up of nitrogen gas?

• 95%

• 21%

• 50%

• 78%

What is the process called when bacteria convert nitrogen into ammonia?

• Denitrification

• Ammonification

• Nitrogen fixation

• Nitrification

Which molecule is a primary energy source for heterotrophs in the phosphorus cycle?

• DNA

• RNA

• ATP

• Proteins

How do phosphates typically enter streams and rivers?

• Through atmospheric deposition

• By erosion of rocks

• Via plant absorption

• Through animal waste

What is the main role of decomposers in the phosphorus cycle?

• To break down plant and animal matter

• To erode rocks

• To release carbon dioxide

• To fix nitrogen