Cycle Of Matter

Carbon, nitrogen, and water are recycled through ecosystems many times. Which one of these eventually breaks down completely? A.Carbon B.Water C.nitrogen

nitrogen

Once water vapor has been released into the atmosphere, it rises and cools, turning back into a liquid. What is this process called? A.evaporation B.condensation C.fixation D.precipitation

Condensation

Which statements accurately describe the roles of decomposers in the carbon cycle? Select three options. A.Decomposers release carbon dioxide into the air as waste. B.Decomposers remove carbon dioxide from the air during photosynthesis. C.Decomposers break down the remains of dead plants and animals. D.Decomposers return carbon compounds to the soil. E.Decomposers use carbon to make food molecules.

Decomposer return carbon compounds to the soil Decomposer break down the remains of dead plants and animals Decomposer release carbon dioxide from the air during photosynthesis

How does the use of fertilizer affect the nitrogen cycle?

Ex: When farmers harvest crops, a lot of the plant material is also removed. Little is left to decay and return nitrogen to the soil. If the soil stays this way, it will start producing fewer crops. Fertilizer contains the nitrogen compounds that are essential for plant growth. It can be used to replace the nitrogen in the soil to ensure the growth of healthy crops.

Explain how human activity can affect the carbon cycle.

Example: Human activity can affect the amount of carbon in the atmosphere. When fossil fuels like oil, coal, and natural gas are burned, carbon dioxide is released into the atmosphere as waste. The clearcutting of forests for lumber and fuel also increases levels of carbon dioxide in the atmosphere because the trees can no longer remove carbon dioxide from the atmosphere for photosynthesis. If trees are burned in order to be cleared, the burning processes release even more carbon dioxide into the air.

What is free nitrogen? A.nitrogen that is ready for plants to use B.nitrogen that has been fixed by bacteria C.nitrogen that cannot be used by organisms D.nitrogen that is returned to the soil by decomposers

Nitrogen that cannot be used by organisms

How do plants obtain nitrogen? A.They remove it from the air. B.They absorb it through their roots. C.They fix it in their leaves. D.They produce it in their stems.

They absorb it through their roots