nitrogen cycle Flashcards
Q1: What is the nitrogen cycle?
A1: The movement of nitrogen through air, soil, plants, animals, and back.
Q2: Why is nitrogen important?
A2: It helps make proteins and DNA for growth.
Q3: What percent of air is nitrogen gas (Nā)?
A3: 78%.
Q4: Can plants use nitrogen gas directly?
A4: No, it must be converted first.
Q5: What is nitrogen fixation?
A5: Turning nitrogen gas into usable forms like ammonia.
Q6: What does nitrogen-fixing?
A6: Bacteria and lightning.
Q7: What are nitrates?
A7: A form of nitrogen plants can absorb from soil.
Q8: What is denitrification?
A8: When bacteria turn nitrates back into nitrogen gas.
Q9: How do humans affect the nitrogen cycle?
A9: By using fertilizers and causing pollution.
Q10: What happens if too much nitrogen enters water?
A10: It causes algae blooms, which harm ecosystems.
What is ammonification?
A11: Decomposers turn dead plants and animals into ammonia.
Q12: What is nitrification?
A12: Bacteria turn ammonia into nitrites and then nitrates.
Q13: How do plants get nitrogen?
A13: They absorb nitrates from the soil.
Q14: How do animals get nitrogen?
A14: By eating plants or other animals.
Q15: What is the role of decomposers in the nitrogen cycle?
A15: They break down dead matter, releasing nitrogen back into the soil.
Q16: What happens if the nitrogen cycle is disrupted?
A16: It can cause soil nutrient loss or pollution problems like dead zones in water.
Q17: What is a dead zone?
A17: An area in water with little oxygen caused by excess nitrogen.
Q18: What do legumes (like beans) do in the nitrogen cycle?
A18: They have nitrogen-fixing bacteria in their roots.
Q19: What are the main processes of the nitrogen cycle?
A19: Nitrogen fixation, ammonification, nitrification, and denitrification.
Q20: How does lightning help the nitrogen cycle?
A20: It converts nitrogen gas into forms plants can use.
Q21: What human activities add nitrogen to the environment?
A21: Using fertilizers, burning fossil fuels, and farming livestock.
Q22: How can we reduce nitrogen pollution?
A22: Use less fertilizer, plant cover crops, and manage animal waste properly.
Q23: What is leaching?
A23: When nitrates are washed out of soil into water by rain.
Q24: What is eutrophication?
A24: Excess nutrients like nitrogen in water causing algae growth and harming ecosystems.
