Carbon cycle
Marine sediments that form limestone are a major sink for this element.
a)carbon
b)sulfur
c)phosphorus
Guano from fish-eating birds is a commercial source of this element.
phosphurous
A field is abandoned, and an invasive plant that can live in nutrient-poor soil moves into the field. If the land is later cleared of this invasive species and it is discovered that the soil has an abundance of nitrogen compounds, what conclusion can best be made?
Bacteria in soil and in root nodules converted free nitrogen into nitrogen compounds.
what best describes gross primary productivity in an ecosystem?
Gross primary productivity is the total amount of solar energy captured by producers through photosynthesis over time.
An energy transformation occurs and results in increased disorder.
How does the burning of fossil fuels contribute to the net increase in atmospheric carbon?
A)Photosynthesis is reduced by virtue of increased smoke and haze.
b) Carbon released by the burning is not in a form that can be readily absorbed by plants, leaving residual carbon in the atmosphere.
c) Carbon that has been sequestered underground is added to the carbon cycling between the atmosphere and the biosphere.
d) Carbon released by the burning is more easily absorbed in the atmosphere than that produced by natural means.
e) Carbon released by the burning increases plant growth, producing more carbon for the atmosphere.
c) Carbon that has been sequestered underground is added to the carbon cycling between the atmosphere and the biosphere.
Which of the following best helps to explain why phosphorus is often a limiting factor in many ecosystems?
Under many conditions, phosphorus forms stable insoluble compounds.
Nitrate ions and nitrite ions are converted into nitrous oxide gas and nitrogen gas (N2).
dentrification.
The ultimate source of energy for terrestrial ecosystem is
the sun
Losses of usable energy between successive trophic levels in an ecosystem are best accounted for by which of the following?
The second law of thermodynamics
Which of the following is true of carbon as it cycles in nature?
Carbon sinks include forests and oceans.
Ammonia is converted to nitrite, then to nitrate.
nitrification
an area that was once a pasture that has since undergone changes to the vegetation over time. Which of the following changes in the hydrologic cycle is most likely to occur as a result of the change in vegetation in the area?
increased infiltration
The atmospheric concentration of carbon dioxide increased from 278 ppm in 1790 to 383 ppm in 2007. What is the approximate percent increase in carbon dioxide concentration from 1790 to 2007?
38%
first law of thermodynamics
heat is increased work is decreased