Matter and Energy in the Environment # 5

Front

What is the nitrogen cycle?

Back

The nitrogen cycle is the process by which nitrogen is converted between its various chemical forms, including nitrogen gas, ammonia, nitrites, and nitrates, through biological and physical processes.

Front

How do bacteria contribute to the nitrogen cycle?

Back

Bacteria convert nitrogen gas into ammonia through a process called nitrogen fixation, making nitrogen available for plants.

Front

What are the three processes that add inorganic phosphate (PO4^3-) to the soil?

Back

Precipitation, runoff, and weathering of rock contribute to the addition of inorganic phosphate to the soil.

Front

How does phosphorus enter the soil?

Back

Phosphorus enters the soil through the weathering of rocks, decomposition of organic matter, and application of fertilizers.

Front

What is primary productivity?

Back

Primary productivity is the rate at which plants and other photosynthetic organisms produce organic compounds in an ecosystem.

Front

What effect does increasing nitrogen and phosphorus availability have on primary productivity?

Back

Increasing the availability of nitrogen and phosphorus typically leads to an increase in primary productivity.

Front

What percentage of the atmosphere is made up of nitrogen?

Back

Approximately 78% of the atmosphere is composed of nitrogen.

Front

What role do decomposers play in nutrient cycling?

Back

Decomposers break down dead organic matter, returning nutrients to the soil and making them available for plants.

Front

What is the significance of weathering in nutrient cycling?

Back

Weathering breaks down rocks, releasing essential nutrients like phosphorus and potassium into the soil.

Front

What is the process of nitrogen fixation?

Back

Nitrogen fixation is the conversion of nitrogen gas from the atmosphere into ammonia or related compounds in soil, primarily by bacteria.