03.3 AA

Which elements are required by living cells in relatively large amounts?

• Oxygen, hydrogen, carbon, nitrogen, phosphorus, and potassium

• Iron, calcium, sodium, magnesium, zinc, and copper

• Sulfur, chlorine, iodine, manganese, boron, and molybdenum

• Silicon, aluminum, titanium, vanadium, chromium, and nickel

What are essential nutrients?

• Elements that can be manufactured by organisms

• Elements that are used up by organisms

• Elements that serve as building blocks for living tissue

• Elements that are recycled within ecosystems

How do organisms obtain essential nutrients?

• By manufacturing them through biological processes

• By reusing them from previous cycles

• By absorbing them from the atmosphere

• By obtaining them from external sources

What are biogeochemical cycles?

• Cycles that involve only biological processes

• Cycles that involve geological and physical processes

• Cycles that involve chemical reactions in the atmosphere

• Cycles that involve human activities

Which processes are involved in biogeochemical cycles?

• Biological processes, geological processes, and physical and chemical processes

• Biological processes, human activities, and atmospheric processes

• Geological processes, physical and chemical processes, and human activities

• Human activities, atmospheric processes, and biological processes

What are examples of biological processes?

• Volcanic eruptions and rock formation

• Cloud formation and precipitation

• Photosynthesis and respiration

• Mining and burning fossil fuels

Which sphere is mainly involved in geological processes?

• Biosphere

• Hydrosphere

• Atmosphere

• Geosphere

What are physical and chemical processes?

• Processes that involve the flow of water and the action of lightning

• Processes that involve photosynthesis and respiration

• Processes that involve volcanic eruptions and rock formation

• Processes that involve mining and burning fossil fuels

How have human activities affected biogeochemical cycles?

• By increasing the availability of essential nutrients

• By reducing the flow of energy in ecosystems

• By causing measurable changes in the Earth system

• By reusing elements in the biosphere

What is the water cycle?

• The cycle of water vapor in the atmosphere

• The cycle of water through the hydrosphere, atmosphere, geosphere, and biosphere

• The cycle of water absorption by plants

• The cycle of water runoff into rivers and streams