Chapter 25 Cycling Carbon

CO2 is added to the atmosphere by:

2 of the above

Which of the following statements is TRUE about photosynthesis and chemical weathering?

Both processes use CO2 as a reactant (i.e., decrease atmospheric CO2 levels).

Which of the following equations is the chemical reaction for cellular respiration?

C6H12O6 + 6O2 → 6CO2 + 6H2O

What can Antarctic ice core samples tell us about atmospheric CO2 levels?

CO2 ice core data confirm CO2 measurements taken directly from the atmosphere. Ice cores can help scientists estimate atmospheric CO2 levels from centuries ago.

If a forester treats his soil with a broad-spectrum fungicide, how would this affect the rate of CO2 released from the system?

CO2 released from the system will decrease because this would decrease the number of decomposers in the system.

Which of the following represents an accurate description of the movement of carbon through a food web?

Carbon is removed by the producers, and added by the consumers.

Which of the following could provide and explanation for the rapid increase in oxygen levels 2.5 billion years ago?

Sedimentation rates increased, photosynthesis rates increased, and respiration rates were low

Over the last several decades, what have researchers discovered about atmospheric CO2 levels?

They have increased

There is evidence that increased levels of CO2 in the atmosphere may increase Earth's surface temperature. How might this affect the spread of mosquitoes and malaria?

Warmer temperatures may result in malaria causes in new regions Warmer temperatures may increase the habitat range of mosquitoes

Since CO2 is a greenhouse gas, a rise in CO2 levels correlates with:

a rise in temperature

The levels of CO2 in the atmosphere have been

increasing

The ___ cycle deals with geological processes and carbon reservoirs, some of which have been built up (or take place) over a period of millennia. In contrast the ____ cycle involves biological processes that are carried out on a daily and/or seasonal basis

long term carbon ; short term carbon

The movement of carbon from CO2 in the atmosphere to HCO3- ( a byproduct of chemical weathering) on rocks to CaCO3 in coral skeletons and finally CaCO3 in limestone are all steps in the

long term carbon cycle

Recall that in the northern hemisphere, atmospheric CO2 levels are highest in early spring and lowest in early fall. What accounts for this seasonal fluctuation in atmospheric CO2 levels?

photosynthesis

The carbon in a good web primarily comes from:

primary producers

The rate of respiration _____ throughout the year

remains more or less constant

Photosynthesis ____ the atmosphere , whereas respiration ___ the atmosphere

removes CO2 from; introduces CO2 to

Recall that sedimentary rocks, living organisms, oceans, and soil are all carbon reservoirs. If the carbon in each of these reservoirs was instantly transformed into atmospheric CO2, which reservoir would contribute the MOST CO2 to the atmosphere?

sedimentary rocks

Photosynthesis and respiration both play a major role in the ____ carbon cycle, and can affect atmospheric CO2 levels on a seasonal or annual basis

short term

Which of the following processes is responsible for the changes in scientists observed in atmospheric concentration of 12C, 13C, and 14C over the last 200 years?

the burning of fossil fuels

When looking at the carbon isotopes present in the atmosphere, scientists determined that 13C and 14C levels have increased over time. What did researchers conclude from these observations?

the use of fossil fuels is responsible

Which of the following processes INCREASES the amount of CO2 in the atmosphere

volcanic eruptions respiration

Photosynthesis and respiration affect atmospheric of CO2 levels on a ___ timescale, wheres volcanic eruptions affect atmospheric CO2 levels on a _____ timescale

yearly; century