The Carbon Cycle

Multiple Choice

The circulation of the element Carbon among Earth's atmosphere, land, oceans, and organisms is called _____________.

• the Carbon Cycle

• the Oxygen Cycle

• the Carbon dioxide Cycle

• the Water Cycle

Multiple Choice

When humans burn fossil fuels, most of the carbon quickly enters the                       as carbon dioxide.

• Water
• Atmosphere
• Sun
• Air

Multiple Choice

_____________ is an essential element of all living creatures.

• Gold

• Carbon

• Carbon dioxide

• Silver

Multiple Choice

Which one of these does not add CO2 to the atmosphere?

• cooking with gas
• planting trees
• burning wood
• riding in a bus

Multiple Choice

The total amount of the carbon on Earth is constant.

• True

• False

Multiple Choice

Combustion is another word for _______________.

• a train
• a bus
• a dog
• burning

Multiple Choice

Carbon is used in the process called __________ by plants and algae to make food and the building blocks for growth.

• carbon cycle

• life

• photosynthesis

• decomposition

Multiple Choice

What does not produce carbon dioxide?

• Photosynthesis
• Burning Fossil Fuels
• Animal respiration
• Plants decaying

Multiple Choice

Bacterias that decompose dead plants release _____________ back into the atmosphere.

• water

• nitrogen

• oxygen

• carbon

Multiple Choice

How do living organisms return carbon to the atmosphere in the carbon cycle?

• respiration and photosynthesis
•  decomposition and respiration

Multiple Choice

In the oceans; algae, plants, and other organisms use carbon from the atmosphere for ________________.

• respiration

• decomposition

• transpiration

• photosynthesis

Multiple Choice

In the carbon cycle, producers take in the gas __

• carbon dioxide
• oxygen
• nitrogen
• carbon monoxide

Multiple Choice

Organisms that die in the ocean may __________ to the bottom and form limestone rock of a period of time.

• sink

• float

• rise

• increase

Multiple Choice

How does the carbon in grass become part of a lion?

• The lion eats the grass
• Carbon from grass doesn't end up in a lion. 
• The carbon ends up in the lion's food chain. 
• The lion breathes in carbon given out by the plant

Multiple Choice

Ocean coral and oysters use carbon to create _________.

• oxygen

• shells

• leaves

• food

Multiple Choice

In what process is Carbon transformed into chemical energy?

• Photosynthesis
• Respiration
• Primary Production
• Secondary Production

Multiple Choice

Limestone is a type of rock created from the ______________ of dead sea organisms.

• waste

• slime

• shells

• unknown

Multiple Choice

Over ________________ of years, once-living matter that remains in the ground can transform into fossil fuels.

• millions

• hundreds

• thousands

• a few handful

Multiple Choice

Since the mid- 1800's, _____________ activity has significantly altered the carbon cycle.

• animal

• plant

• unknown

• human

Multiple Choice

Burning fossil fuels has raised the concentration of ___________ in the atmosphere.

• oxygen

• rain

• carbon

• nitrogen