nitrogen cycle

How much of the atmosphere is composed of nitrogen gas?

• 87%
• 38%
• 78%
• 21%

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

• nitrogen composition
• ammonia 
• nitrogen fixation
• denitrification

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.

Plants and animals cannot use nitrogen directly from the air.

• True
• False

What happens when organisms die and decay? 

• Their bodies are lifted up
• Their nitrogen returns to the soil
• they keep their nitrogen
• They stay on earth forever

Tags

NGSS.MS-LS2-3

The process in which Nitrogen circulates and is recycled is called ____________

• The nitrogen cycle
• The water cycle
• The carbon cycle
• Nitrogen Fixation 

Tags

NGSS.MS-LS2-3

_____ is the conversion of organic nitrogen into ammonia

• Nitrogen Fixation
• Ammonification
• Denitrification
• Assimilation 

Nitrification happens in the ______

• Air 
• Soil 
• Ground Water 
• Plants 

Tags

NGSS.MS-LS2-3

What converts nitrogen gas into a usable form for plants and animals?

• bacteria

• rain

• fungi

• car exhaust

How do animals get the nitrogen they need?

• From the air they breathe

• From the water they drink

• From the food they eat

• From the sun

Tags

NGSS.MS-LS2-3