The Carbon Cycle

The carbon cycle is

• oxygen moving throughout the ecosystem

• carbon being recycled over and over from the atmosphere to plants, to animals, and back to the atmosphere.

• nitrogen being recycled over and over from the atmosphere to plants, to animals, and back to the atmosphere.

• carbon atoms floating in circles

The burning of fossil fuels is called

• osmosis

• photosynthesis

• respiration

• combustion

Fossil fuels are

• carbon in the ground that is used to make oil, gas, and coal.

• energy for photosynthesis

• really old oxygen

• carbon dioxide gas

CO2 =

• oxygen gas

• carbon dioxide

• carbon monoxide

• glucose

Carbon is released into the atmosphere by

• combustion

• cell respiration

• decomposers

• all of the above

Carbon is a gas in the atmosphere in the form of

• O2

• C

• CO2

• C6H12O6

Which of the following is a true statement?

• There is not enough carbon dioxide in the atmosphere.

• Humans breathe in too much carbon

• Humans put more carbon into the atmosphere than we removed from it.

• Combustion is not a problem for the carbon cycle.

Which of the following is NOT true?

• Cars burn gas, which puts carbon dioxide into the atmosphere.

• Factories and power plants release carbon dioxide into the atmosphere.

• We need to cut down more trees to help with the carbon cycle.

• Deforestation is the removal of plants.

We use _____ and breathe out _____.

• carbon dioxide, oxygen

• oxygen, carbon dioxide

• carbon dioxide, glucose

• glucose, sunlight

Plants take in ____ through their leaves and release ____ into the atmosphere.

• Glucose, ATP

• Carbon dioxide, glucose

• carbon dioxide, oxygen

• ATP, oxygen