How many questions are in this quiz?

This quiz has 119 questions covering carbon, nitrogen, and phosphorus cycling.

What format are the questions in?

Each question has 4 answer options and there is no timer, so you can work at your own pace.

Is the difficulty suitable for beginners and advanced learners?

Yes. It’s mixed difficulty, combining foundational concepts with more applied ecology and biogeochemistry scenarios.

Can I choose how many questions to answer?

Yes. You can select your question count and difficulty before you begin to match your study time and goals.

What topics are most emphasized?

Expect reservoirs and fluxes, key processes (fixation, nitrification, denitrification), phosphorus weathering and runoff, and human impacts like eutrophication and CO2 emissions.

Online Quiz: Nutrient cycles: C, N & P

About this quiz

What you’ll practice

Move confidently between the carbon, nitrogen, and phosphorus cycles by identifying reservoirs, fluxes, and the organisms driving each step. You’ll also connect real-world issues—like eutrophication and climate change—to the underlying biogeochemistry.

Every question uses 4 options and there’s no timer, so you can slow down to reason through pathways, units, and cause-and-effect.

Common pitfalls to avoid

Many learners mix up where each cycle has a major atmospheric component (carbon and nitrogen) versus where it does not (phosphorus). Another frequent slip is confusing similar processes—like nitrification vs. denitrification—or treating decomposition as separate from nutrient cycling.

Mixing nitrification (NH4+ → NO3−) with denitrification (NO3− → N2)
Forgetting phosphorus lacks a significant gaseous phase in most models
Confusing assimilation by plants with mineralization by decomposers
Overlooking human inputs (fertilizer, fossil fuels) when explaining flux changes
Treating “reservoir” and “flux” as interchangeable terms

Difficulty and question settings

Difficulty is balanced across the set: you’ll see straightforward definitions, then progressively more applied questions using scenarios (e.g., runoff, algal blooms, soil oxygen levels). Choose your preferred question count and difficulty before starting—short runs are great for quick review, while longer sessions build endurance across all subtopics.