The Importance of Carbon

Where is the greatest amount of the world’s carbon found?

• atmosphere

• seafloor sediments

• ocean

• plants and animals

In what form is carbon found in the atmosphere?

• CO2

• C6H12O6

• H2O

• ATP

Which statement best describes the relationship between photosynthesis and cellular respiration?

• Photosynthesis removes carbon from the atmosphere, and cellular respiration releases carbon back into the atmosphere.

• Photosynthesis is part of the carbon cycle, and cellular respiration is not.

• Only plants perform

• Photosynthesis releases carbon into the atmosphere, and cellular respiration removes carbon from the atmosphere.

The carbon cycle ensures that carbon is not lost. Which is another important benefit of the carbon cycle?

• The carbon cycle ensures that living things have a continual source of hydrogen.

• The carbon cycle helps transport nutrients in bodies of water.

• The carbon cycle helps regulate Earth's temperature.

• The carbon cycle ensures that there is a continual supply of water.

Which macromolecule provides the blueprint for living things by storing and transmitting genetic information?

• protein

• carbohydrate

• lipid

• nucleic acid

Look at the levels of carbon dioxide in the data table below.

Carbon in the Atmosphere

What quantity of carbon dioxide was in the atmosphere in 1980?

• 317 ppm

• 326 ppm

• 339 ppm

• 371 ppm

Which substance is considered a building block for all living things?

• hydrogen

• glucose

• carbon

• protein

Which reason best explains why living things need carbon?

• Carbon is a source of energy.

• Carbon reduces global temperatures.

• Carbon is an important solvent.

• Carbon is everywhere.

Which reason best explains why carbon is able to form macromolecules?

• Carbon is a very large element.

• Carbon can bond with many elements.

• Carbon is found in all living things.

• Carbon is found in energy-storing molecules.

Which pair of molecules both contain carbon atoms?

• fats and proteins

• water and carbohydrates

• nucleic acids and water

• oxygen gas and fats