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