AP BIOLOGY

Detailed explanation-1: -The correct answer is Phosphorus cycle. The phosphorus cycle is the biogeochemical cycle that describes the movement of phosphorus through the lithosphere, hydrosphere, and biosphere.

Detailed explanation-2: -Human-Induced Changes The human mobilization of carbon, nitrogen, and phosphorus from the Earth’s crust and atmosphere into the environment has increased 36, 9, and 13 times, respectively, compared to geological sources over pre-industrial times.

Detailed explanation-3: -A major effect from fertilizer runoff is eutrophication, a process whereby nutrients from the runoff cause the overgrowth of algae and a number of resulting problems (Chapter 16). The phosphorus and sulfur cycles are other critical biogeochemical cycles.

Detailed explanation-4: -Changes to the carbon cycle Human activities have a tremendous impact on the carbon cycle. Burning fossil fuels, changing land use, and using limestone to make concrete all transfer significant quantities of carbon into the atmosphere.

Detailed explanation-5: -Recently, people have been causing these biogeochemical cycles to change. When we cut down forests, make more factories, and drive more cars that burn fossil fuels, the way that carbon and nitrogen move around the Earth changes. These changes add more greenhouse gases in our atmosphere and this causes climate change.