How is carbon passed from plants to animals?

Which process returns carbon dioxide to the atmosphere from living organisms?

Define combustion.

When fossil fuels are burned, carbon combines with oxygen and          is released into the atmosphere.

True or False? Fossil fuels form from dead organisms over millions of years under great pressure.

Why does deforestation increase the carbon dioxide content of the atmosphere?

Carbon dioxide is taken out of the atmosphere by plants for the process of         .

True or False? Carbon is an endless resource that never needs to be recycled.

Under what conditions do dead organisms form fossil fuels?

What name is given to the burning of trees that releases carbon dioxide during deforestation?

Give one human activity that is increasing atmospheric carbon dioxide.

Why do living organisms need nitrogen?

Why can plants and animals not absorb nitrogen gas directly from the air?

Define nitrogen-fixing bacteria.

Where are nitrogen-fixing bacteria found?

Besides bacteria, what natural event can fix nitrogen gas from the air?

Plants absorb       from the soil and use the nitrogen in them to make proteins.

How does nitrogen from animal waste and dead organisms return to the soil?

Define nitrifying bacteria.

True or False? Denitrifying bacteria convert nitrates in the soil back into nitrogen gas.

        bacteria in poorly aerated soil convert nitrates back into nitrogen gas.

How can farmers reduce the activity of denitrifying bacteria?

True or False? Nitrifying bacteria remove nitrates from the soil and release nitrogen gas.