Carbon cycle

Carbon is a common component of

• limestone

• all organisms

• volcanic gases

• all of the choices

The geologic portion of the carbon cycle operates on a scale of days to months

• True

• False

Photosynthesis is the process by which plants

• release carbon dioxide into the atmosphere

• turn carbon dioxide into sugars

• turn sugars into energy

• None of the choices

Respiration is the process by which ____________ is consumed and _______________ is produced.

• carbon dioxide, oxygen

• carbon dioxide, energy

• oxygen,carbon dioxide

• energy,carbon dioxide

Regular, annual fluctuations in atmospheric carbon dioxide concentrations occur because

• photosysthesis stops at night while respiration continues

• Humans influence the carbon dioxide concentrations

• carbon dioxide emmisions increases in winter

• plants in the northern hemisphere lose their leaves during winter.

How does the concentration of carbon dioxide in the atmosphere affect climate?

• As carbon dioxide concentrations increases temperature decreases

• As carbon dioxide concentrations increases temperature increases

• carbon dioxide concentrations have no affect on climate

• as carbon dioxide concentrations increase, temperature becomes more random

According to most scientists, activities like fossil fuel burning and deforestation have affected the global carbon cycle.

• True

• False

Which of the following processes does NOT add carbon to the atmosphere?

• volcanic erruptions

• respiration

• weathering of limestone

• subduction

Although direct measurements of atmospheric carbon dioxide have only been taken consistently since the 1950s, scientists have been able to retrieve data from the past 500,000 years. They have been able to do this by looking at

• ice cores from ice sheets

• sediment cores from the ocean

• tree rings

• all of the choices

A net carbon source is a carbon pool which takes in more carbon than it releases.

• True

• False