Nutrient Cycling MCQs (Quiz 10) Posted on May 30, 2026Author agropublishers 0 1. Which of the following rocks is most resistant to weathering? Limestone Shale Marble Quartzite 2. The rate of weathering generally increases with ____________________ Decreasing moisture Increasing temperature and moisture Increasing rock size Decreasing temperature 3. A farmer adds carbon-rich straw to the soil. Soon afterward, plants show nitrogen deficiency symptoms. What is the most likely explanation? Decomposition of straw acidifies the soil, converting nitrates into gases The straw releases toxins that block nitrogen uptake by plant roots Rainfall triggered by the straw addition leaches nitrogen from the root zone Soil microbes decomposing the carbon-rich straw immobilize available nitrogen in their biomass, temporarily reducing its availability to plants 4. Deforestation causes a “double carbon penalty” because it _______________________________ Reduces oxygen production but does not affect carbon dioxide levels Increases rainfall and removes carbon from the atmosphere Stores more carbon in the soil and increases photosynthesis Releases carbon stored in trees and reduces the forest’s ability to absorb CO₂ in the future 5. Salt weathering is also known as _______________ Haloclasty Hydroclasty Cryoclasty Thermoclasty 6. A peat bog stores large amounts of carbon accumulated over thousands of years. When drained and burned, it releases CO₂ into the atmosphere. In this scenario, the peat bog has changed its role to _____________________________ A decomposer, as it is breaking down organic matter A recycler, as it is returning carbon to the soil A nutrient source, as it is now releasing stored carbon into the environment A nutrient sink, as it is absorbing more carbon 7. Which of the following best represents a nutrient budget in an ecosystem? The speed at which plants absorb minerals from the soil The number of trophic levels through which nutrients pass The cost of adding fertilizers to agricultural land The total amount of nutrients entering, leaving, and being stored in an ecosystem 8. Why is atmospheric CO₂ increasing despite the presence of natural carbon sinks? The oceans no longer contain dissolved carbon Human emissions exceed the capacity of natural sinks to absorb carbon Natural sinks absorb carbon faster than humans release it Photosynthesis has stopped globally 9. Organic nitrogen in waterlogged soil is converted into _______ during ammonification Nitrite ions, because nitrogen is partially oxidized in anaerobic soils Nitrate ions, because nitrifying bacteria are active without oxygen Nitrogen gas, because ammonification directly releases gaseous nitrogen Ammonium ions, because oxygen is absent and nitrification cannot occur 10. Which rock characteristic most strongly affects weathering susceptibility? Rock age alone Mineral composition Rock location Rock color Loading … Question 1 of 10
