Previous year UPSC prelims questions – Nutrient Cycle | Biogeochemical Cycle

1. Which of the following are nitrogen-fixing plants?

1. Alfalfa
2. Amaranth
3. Chickpea
4. Clover
5. Purslane (Kulfa)
6. Spinach

Select the correct answer using the code given below: [UPSC Civil Services Exam – 2022 Prelims]

2. In case of which one of the following biogeochemical cycles, the weathering of rocks is the main source of release of nutrient to enter the cycle? [UPSC Civil Services Exam – 2021 Prelims]

3. What is blue carbon?

[UPSC Civil Services Exam – 2021 Prelims]

4. Which of the following adds/add carbon dioxide to the carbon cycle on the planet Earth?

1. Volcanic action
2. Respiration
3. Photosynthesis
4. Decay of organic matter

Select the correct answer using the code given below. [UPSC Civil Services Exam – 2014 Prelims]

5. Which of the following adds/add nitrogen to the soil?

1. Excretion of urea by animals
2. Burning of coal by man
3. Death of vegetation

Select the correct answer using the code given below: [UPSC Civil Services Exam – 2013 Prelims]

6. Consider the following:

1. Photosynthesis
2. Respiration
3. Decay of organic matter
4. volcanic action

Which of the above add carbon dioxide to the carbon cycle on Earth? [UPSC Civil Services Exam – 2011 Prelims]