Ecosystem Dynamics: Energy and Matter in Balance

Which of the following best describes a food web?

• A linear sequence of organisms through which nutrients and energy pass

• A complex network of interconnected food chains

• A graphical representation of the amount of energy at each trophic level

• A cycle that shows the flow of water through an ecosystem

In the carbon cycle, which process is responsible for the release of carbon dioxide into the atmosphere?

• Photosynthesis

• Decomposition

• Respiration

• Nitrogen fixation

What is the primary role of nitrogen-fixing bacteria in the nitrogen cycle?

• Converting nitrogen gas into nitrates

• Breaking down organic matter to release nitrogen

• Converting nitrates into nitrogen gas

• Absorbing nitrogen from the atmosphere

What does an energy pyramid represent in an ecosystem?

• The number of organisms at each trophic level

• The biomass at each trophic level

• The flow of energy from one trophic level to the next

• The amount of carbon at each trophic level

Which type of aquatic ecosystem is characterized by the presence of standing water?

• River

• Estuary

• Lake

• Ocean

What does a biomass pyramid illustrate in an ecosystem?

• The distribution of species across different habitats

• The amount of living organic matter at each trophic level

• The number of individual organisms at each trophic level

• The flow of water through different trophic levels

In a pyramid of numbers, what does each level of the pyramid represent?

• The amount of energy available at each trophic level

• The biomass present at each trophic level

• The number of individual organisms at each trophic level

• The number of species at each trophic level

Which process in the water cycle involves water vapor cooling and changing into liquid form?

• Evaporation

• Condensation

• Precipitation

• Transpiration

In an energy pyramid, which trophic level typically has the most energy available?

• Top predators

• Herbivores

• Primary producers

• Decomposers

What process in the nitrogen cycle involves the conversion of ammonia into nitrite and then into nitrate?

• Denitrification

• Nitrification

• Ammonification

• Nitrogen fixation