Topic 5: Cycles in the Environment

What happens when animals exhale during respiration?

• Oxygen is released into the atmosphere

• Carbon dioxide (CO2) is recycled into the air

• Nutrients are returned to the soil

• Energy is released into the environment

What role do plants play in the carbon cycle?

• They release CO2 into the atmosphere through respiration

• They absorb CO2 from the atmosphere and convert it into sugars

• They break down carbon in the soil

• They release carbon dioxide during photosynthesis

How is carbon returned to the soil in the carbon cycle?

• By animals exhaling CO2

• Through the burning of fossil fuels

• When plants and animals decompose

• When water evaporates into the atmosphere

What is one major way humans add carbon dioxide to the atmosphere?

• By planting trees

• Through the burning of fossil fuels

• By photosynthesis

• Through the water cycle

Which process describes the change of water from liquid to vapor?

• Precipitation

• Condensation

• Transpiration

• Evaporation

Which process in the water cycle involves water vapor forming clouds?

• Evaporation

• Condensation

• Precipitation

• Transpiration

What is pollution?

• The natural breakdown of harmful substances in the environment

• The excessive introduction of harmful substances into the environment

• The release of oxygen into the atmosphere by plants

• The evaporation of water into the air

What is acid rain?

• Rain that has a neutral pH

• Rain formed when pollutants mix with water vapor

• Rain that helps plants grow faster

• Rain formed when CO2 combines with nitrogen

What is bioaccumulation?

• The build-up of pollutants like mercury in organisms through the food web

• The process of photosynthesis in plants

• The collection of water vapor in the atmosphere

• The recycling of carbon dioxide in the carbon cycle

Which pollutant is known to accumulate in large fish through bioaccumulation?

• Nitrogen oxide

• Mercury

• Sulfur dioxide

• DDT