Nutrient Cycling MCQs (Quiz 6) Posted on May 30, 2026Author agropublishers 0 1. What is the correct sequence of products formed during nitrification? N₂ → NH₃ → NO₂⁻ NO₃⁻ → NO₂⁻ → NH₄⁺ NH₄⁺ → NO₂⁻ → NO₃⁻ NH₃ → N₂ → NO₃⁻ 2. Plants mainly absorb water and mineral ions from the soil through their _________________ Stomata Root hair cells Stem vessels Leaves 3. Burning fossil fuels releases large amounts of __________________ gas, directly contributing to the greenhouse effect and global warming Oxygen gas (O₂) Nitrogen gas (N₂) Carbon dioxide (CO₂) Water vapor (H₂O) 4. The breakdown of rocks into soil particles is an important consequence of _____________ Volcanic eruptions Ocean circulation Weathering processes Plate tectonics 5. Which of the following is NOT an agent of nitrogen fixation? Cyanobacteria Mycorrhizal fungi Bacteria associated with legume roots Lightning 6. When a plant absorbs nitrates from the soil and uses them to build proteins, this is an example of ____________ Decomposition Denitrification Assimilation Excretion 7. Which ecosystem acts as one of the largest natural carbon sinks on Earth? Urban ecosystems Deserts Agricultural fields Oceans 8. Which weathering process directly releases calcium and magnesium ions into soil solution, making them available for plant uptake? Carbonation Thermal expansion Exfoliation Frost wedging 9. Lichens contribute to weathering by ______________________ Removing oxygen from rocks Increasing atmospheric pressure Producing volcanic heat Producing organic acids that dissolve minerals 10. Which type of weathering is most dominant in tropical rainforests? Physical weathering Chemical weathering Frost weathering Glacial weathering Loading … Question 1 of 10
