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WorksheetsNitrogen, Phosphorus, Carbon Cycle - Q3 W2
Total questions: 15
Worksheet time: 51mins
The carbon in coal, oil, and natural gas came from
the combustion of fossil fuels.
the remains of dead organisms.
carbon-fixing bacteria in swamp soil.
carbon dioxide dissolved in ocean water.
How does most of the carbon in an organism’s body return to the environment after the organism dies?
Decomposers break the body down into simpler compounds.
Heat from the sun causes the carbon in the body to evaporate.
Geological processes cause the body to turn into a fossil fuel.
Rainwater dissolves the carbon in the body and carries it to the ocean.
Human processes mainly contribute to the
release of carbon dioxide into the atmosphere.
decrease of the total amount of carbon found on Earth.
depletion of carbon dioxide reserves in the atmosphere.
increase in the amount of carbon contained in rock materials.
Nitrogen, in the form of ammonia, nitrate, and nitrite, is found in the soil.
True
False
Nitrogen fixation is the process in which certain bacteria convert nitrogen gas into nitrates.
True
False
Denitrification is the process by which some soil bacteria convert nitrates into nitrogen gas.
True
False
All organisms require nitrogen to make amino acids, which in turn are used to build carbohydrates.
True
False
Phosphate is released as rocks and sediments wear down.
True
False
Plants absorb phosphate from the soil or from water
True
False
Phosphorus is the most abundant gas in the atmosphere.
True
False
Phosphorus forms part of the important life-sustaining molecules such as DNA and RNA.
True
False
Plants absorb phosphorus from the atmosphere or water.
True
False
How do humans add nitrogen to the biosphere?
If a nutrient were in short supply in an ecosystem, how might it affect an organism?
How might building a new highway affect the cycles of matter?
