Nutrient Cycling MCQs (Quiz 5) Posted on May 30, 2026Author agropublishers 0 1. In the context of nutrient cycling, leaching is best defined as ____________________ The biological conversion of nitrates into atmospheric nitrogen gas The downward movement of water through soil that carries dissolved nutrients away from the root zone The addition of mineral nutrients to soil through weathering of bedrock The microbial breakdown of organic matter releasing inorganic nutrients 2. Why does the combustion of fossil fuels disrupt the natural carbon cycle? It permanently removes carbon from biological systems It converts atmospheric nitrogen into carbon dioxide It prevents carbon fixation by plants It transfers carbon from long-term geological storage to the atmosphere rapidly 3. Which weathering agent is considered the most important overall? Temperature Gravity Wind Water 4. Deforestation accelerates climate change primarily because it ____________ Decreases the capacity of ecosystems to absorb atmospheric CO₂ Reduces phosphorus weathering rates Enhances decomposition of carbonate rocks Increases nitrogen fixation in forest soils 5. Rust formation on rocks is an example of ______________ Carbonation Exfoliation Oxidation Hydrolysis 6. Which of the following is an example of a nutrient source in the carbon cycle? Soil storing organic carbon A growing forest absorbing CO₂ A volcano releasing CO₂ into the atmosphere Ocean water dissolving atmospheric CO₂ 7. A major perturbation of the carbon cycle by human activity is associated with _____________________ Removal of carbon from the atmosphere in fertilizer production Accelerated removal of carbon from the atmosphere by forests Respiratory production of CO₂ by the human population Release of carbon from fossil fuel deposits 8. Which substance is the starting material for nitrification? Ammonia / Ammonium (NH₃ / NH₄⁺) Nitrogen gas (N₂) Nitrate (NO₃⁻) Urea 9. Hydrolysis of minerals involves _____________ Expansion of water in minerals upon freezing Physical fragmentation of minerals by wind Reaction of water with minerals to form new substances Reaction between oxygen and minerals 10. Which of the following minerals is highly susceptible to solution weathering? Rock salt Quartz Mica Feldspar Loading … Question 1 of 10
