🌾 The Nitrogen Cycle
This quiz explores the nitrogen cycle—one of Earth's most essential biogeochemical cycles. You'll trace how nitrogen moves from the atmosphere through bacteria, plants, animals, and back to the soil and air. Learn how living organisms depend on nitrogen availability and how human activities like agriculture can impact this delicate balance. **What you'll learn:** - How nitrogen-fixing bacteria convert atmospheric nitrogen into usable forms - The role of plants, animals, and decomposers in the nitrogen cycle - How denitrifying bacteria return nitrogen to the atmosphere - The environmental impacts of fertilizer runoff and eutrophication
Questions in this quiz
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- Question 1
Which type of bacteria is primarily responsible for converting atmospheric nitrogen (N₂) into ammonia (NH₃) that plants can use?
- Question 2
Nitrogen-fixing bacteria live freely in the soil and cannot form symbiotic relationships with plants.
- Question 3
After plants absorb nitrogen from the soil, what is the next step in the nitrogen cycle when herbivores eat these plants?
- Question 4
What role do decomposers play in the nitrogen cycle?
- Question 5
Denitrifying bacteria convert nitrogen compounds in the soil back into atmospheric nitrogen gas (N₂).
- Question 6
In legume plants like peas and beans, nitrogen-fixing bacteria live inside structures called _____, where they receive carbohydrates and provide usable nitrogen.
- Question 7
What is eutrophication, and how is it related to the nitrogen cycle and agriculture?
- Question 8
Artificial nitrogen fertilizers can improve crop yields but also pose environmental risks if excess runoff enters water systems.
- Question 9
Which of the following best describes how nitrogen becomes available to organisms in the nitrogen cycle?
- Question 10
What is a key environmental benefit of crop rotation that includes legumes (such as planting clover)?
- Question 11
Nitrogen is an essential element for all living organisms because it is a key component of proteins and nucleic acids (DNA and RNA).
- Question 12
In the nitrogen cycle, which organisms are responsible for the initial conversion of atmospheric nitrogen into a form that plants can use?
- Question 13
How does excess agricultural runoff containing nitrogen affect aquatic ecosystems?
- Question 14
All bacteria in the soil play an identical role in the nitrogen cycle.
- Question 15
Which of the following farming practices would MOST help reduce nitrogen runoff and protect water quality?