The Carbon Cycle Flashcards

All 6 cards in this deck

Why must materials such as carbon and nitrogen be recycled through the abiotic and biotic components of an ecosystem?

The supply of these elements is limited, and organisms need them to build the molecules (e.g. carbohydrates, proteins) needed for growth.

Name the processes that release carbon dioxide into the atmosphere in the carbon cycle.

Respiration (by plants, animals and decomposers), combustion of fossil fuels and volcanic activity.

What is the role of decomposers (bacteria and fungi) in the carbon cycle?

They break down dead organisms and waste, and release carbon dioxide when they respire; they also return mineral ions to the soil.

In global carbon-flux data, what does it mean if the total carbon released into the atmosphere each year is greater than the total absorbed?

Atmospheric carbon dioxide is rising.
e.g. released 216.0 gigatonnes vs absorbed 212.9 gigatonnes per year means a rise

True or false? In the carbon cycle, carbon passes from plants to animals as carbon dioxide.

False. It passes as carbon compounds (e.g. glucose) when the plants are eaten; carbon dioxide is the form moved between organisms and the atmosphere.

Which process in the carbon cycle takes carbon dioxide out of the air and into living organisms?

Photosynthesis. Plants and algae take in carbon dioxide and build its carbon into glucose and other carbon compounds.