Exam 22: Biogeochemical Cycles

Seasonal fluctuations in atmospheric carbon dioxide concentrations are greater in the Northern Hemisphere than in the Southern Hemisphere.

Nitrogen is available to plants in two forms: ammonium and ________.

Of the carbon actively involved in the global cycle, most is in the oceans.

Most carbon is buried in sedimentary rocks.

The nutrient ________ does not have a gaseous cycle because it occurs in only very minute amounts in the atmosphere.

Precipitation can be a significant input of nutrients in ecosystems.

In arctic ecosystems, ________ are used as bioindicators of heavy metal contamination.

Which of the following cycles is thought to be most under biological control?

The difference between the rate of carbon uptake in photosynthesis and the rate of carbon loss due to autotrophic and heterotrophic respiration is the net ________ productivity.

The largest active carbon pool is

The branch of chemistry dealing with the quantitative relationships of elements in combination is called ________.

The biogeochemical cycles of one ecosystem are typically independent from those of other ecosystems.

Compare and contrast biomagnification and bioaccumulation.

Describe how ozone is formed at different levels of the atmosphere and how biological organisms are affected by ozone.

In ________ biogeochemical cycles, the main reservoirs of nutrients are the atmosphere and the oceans.

One way that sulfur enters the atmosphere is through volcanic activity.

Phosphorus is typically in short supply in aquatic and terrestrial ecosystems.

The various biogeochemical cycles are largely independent of one another.

The major source of free oxygen that supports life on Earth is the ________.

Certain anaerobic bacteria are capable of converting nitrogen compounds into gaseous nitrogen.