AP Biogeochemical Cycles

Identify the cycle pictured.

• The Water cycle
• The Carbon cycle
• The Nitrogen cycle
• The Phosphorus cycle

Identify the cycle pictured.

• The Water cycle
• The Carbon cycle
• The Nitrogen cycle
• The Phosphorus cycle.

Which nutrient is not cycled through the atmosphere?

• carbon
• nitrogen
• phosphorous
• water

This is released by the weathering of rocks.

• Carbon
• Oxygen
• Phosphorus
• Nitrogen

If the atmosphere is 78% N₂, why can't we just get our nitrogen by breathing?

• We have no mechanism to break the triple bond of nitrogen between the atoms.
• Our lungs would be damaged by the N2.
• We need Oxygen for cellular respiration.
• The legumes take it up first.

All plants have nitrogen fixing nodules on their roots.

• True
• False

What is the process of combining nitrogen gas with other elements to make nitrogen into usable compounds?

• nitrogen composition
• ammonia 
• nitrogen fixation
• denitrification

When bacteria convert ammonia back into nitrogen in the soil it is called .. 

• Nitrogen Fixation
• Assimilation
• Nitrification
• Denitrification

How much of the atmosphere is composed of nitrogen gas?

• 87%
• 38%
• 78%
• 21%

How do  animals get nitrogen?

• the atmosphere 
• eating other organisms
• bacteria
• lightning