Nitrogen Cycle

What is the largest reservoir that contains about 78% of all atmospheric nitrogen?

• Bacteria

• Atmosphere

• Soil

• Plants

The process where N2 molecules in the air break apart and combine with other atoms to form ammonia.

• Ammonification

• Assimilation

• Nitrification

• Nitrogen Fixation

• Denitrification

Returning nitrogen to the atmosphere by bacteria living deep in swampy sediments is the process ______.

• Ammonification

• Assimilation

• Denitrification

• Nitrogen Fixation

How much of the atmosphere is composed of nitrogen gas?

• 87%
• 38%
• 78%
• 21%

Tags

NGSS.MS-PS1-1

How do plants get the nitrogen they need?

• from the air
• from the soil or water in which they live
• from the Sun
• from broken-down rocks

Tags

NGSS.MS-LS2-3

NGSS.MS-LS2-1

Why do all organisms need nitrogen?

• To live and grow 
• To build phosphorus
• To make oxygen levels grow
• To help blood circulate better

Tags

NGSS.MS-LS2-3

NGSS.MS-LS2-1

NGSS.MS-LS1-5

The swelling on the roots of a soybean are called

• Noodles
• Nitrogen
• Nodules
• Legumes

Tags

NGSS.MS-LS2-1

NGSS.MS-LS1-5

What converts some atmospheric nitrogen into nitrates that organisms can use?

• Sun
• Rain
• Thunder
• Lighting

Which of the following describes the role of nitrogen-fixing bacteria in the nitrogen cycle? Nitrogen-fixing bacteria convert

• nitrates intro nitrogen gas
• ammonia into proteins
• nitrogen gas into ammonia
• proteins into nitrates

Tags

NGSS.MS-LS2-3

Animals obtain the nitrogen they need directly from the

• soil in their habitat
• air they breathe
• plants they eat
• bacteria living within them

Tags

NGSS.5-LS2-1