Which process converts atmospheric nitrogen into forms plants can use?

• Denitrification

• Nitrogen fixation

• Nitrification

• Decomposition

Which group of organisms is directly responsible for nitrogen fixation and denitrification?

• Fungi

• Bacteria

• Producers

• Consumers

Which statement best describes the role of decomposers in the nitrogen cycle?

• They trap nitrogen in rocks.

• They recycle nitrogen from dead material.

• They remove nitrogen from the atmosphere.

• They create new nitrogen atoms.

An increase in fertilizer use can cause which effect?

• Increased biodiversity in lakes

• Eutrophication due to nutrient runoff

• Decreased plant growth

• Depletion of soil minerals

Which process naturally releases phosphorus from rocks into soil and water?

• Weathering and erosion

• Evaporation

• Condensation

• Combustion

Which statement best explains why phosphorus is a limiting nutrient in ecosystems?

• It is not recycled by decomposers.

• It cycles very slowly through the Earth's crust.

• It evaporates quickly.

• It dissolves easily in the atmosphere.

Which human activity most directly increases the rate of eutrophication?

• Planting trees

• Using phosphate detergents

• Reducing fertilizer use

• Adding oxygen to water

Which organisms help return phosphorus to the soil?

• Decomposers

• Herbivores

• Producers

• Scavengers

Compare and contrast the nitrogen and phosphorus cycles by describing one similarity and one difference. Then explain how both cycles demonstrate the connection between living and nonliving components of ecosystems.

Identify one human activity that increases nitrogen or phosphorus in water. Explain its short-term and long-term effects on biodiversity.