Biogeochemical Cycles

Which is NOT a process of the water cycle?

• precipitation
• freezing
• transpiration
• evaporation

The process of plants losing water through their leaves is called ____.

• condensation
• evaporation
• transpiration
• exhaling

What is the most abundant gas in the atmosphere?

• hydrogen
• oxygen
• helium
• nitrogen

Nitrogen that is not combined with other elements and found in the atmosphere as gas is _____.

• free nitrogen
• nitrogen compounds
• ammonia
• nitrates

The type of nitrogen that can be used by producers is called _____.

• free nitrogen
• nitrous oxide
• nitrogen gas
• nitrogen compounds

Why do living things need nitrogen?

• To get energy
• To make amino acids
• To make proteins
• To make proteins AND amino acids

What are the swellings found on the roots of legumes called?

• noodles
• nodularisms
• nodules
• tubers

Where are denitrifying bacteria found?

• In the soil
• Root nodules
• In dead things
• In the atmosphere

Where are nitrogen-fixing bacteria found?

• In the soil
• Root nodules
• In dead things
• In the atmosphere

What happens during the process of nitrogen-fixation?

• Nitrogen compounds turn into free nitrogen
• Free nitrogen turns into nitrogen compounds