The Nitrogen Cycle Pimlico
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nitrogen cycle
made for a-level biology
Questions and Answers
- 1.
How do animals obtain nitrogen?
- A.
By fixing nitrogen from the atmosphere
- B.
By ammonification
- C.
By feeding and digesting plants
- D.
By nitrification
Correct Answer
C. By feeding and digesting plantsExplanation
Animals obtain nitrogen by feeding and digesting plants because plants contain proteins and other nitrogen-containing compounds. When animals consume plants, they break down these compounds during digestion and absorb the nitrogen for their own use. This process allows animals to obtain the necessary nitrogen for protein synthesis and other biological functions.Rate this question:
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- 2.
Nitrogen in the atmosphere is fixated by:
Correct Answer
free-living bacteria and mutualistic bacteriaExplanation
Nitrogen in the atmosphere is fixated by both free-living bacteria and mutualistic bacteria. Free-living bacteria, such as Azotobacter and Clostridium, have the ability to convert atmospheric nitrogen into a usable form through a process called nitrogen fixation. Mutualistic bacteria, such as Rhizobium, form a symbiotic relationship with certain plants, particularly legumes, and help in nitrogen fixation. These bacteria reside in the root nodules of the plants and convert atmospheric nitrogen into ammonia, which can be used by the plants for their growth and development. Therefore, both free-living bacteria and mutualistic bacteria play a crucial role in fixing nitrogen from the atmosphere.Rate this question:
- 3.
Free-living bacteria turn nitrogen into:
Correct Answer
ammonium ionsExplanation
Free-living bacteria have the ability to convert nitrogen gas from the atmosphere into ammonium ions through a process called nitrogen fixation. This is achieved by the enzyme nitrogenase, which is present in these bacteria. Nitrogen fixation is an essential process as it converts atmospheric nitrogen, which is not readily available to most organisms, into a form (ammonium ions) that can be easily used by plants and other organisms as a nutrient source. Ammonium ions can then be taken up by plants and incorporated into organic molecules, playing a crucial role in the nitrogen cycle.Rate this question:
- 4.
Detrification involves removing this element
Correct Answer
oxygenExplanation
Detrification is a process that involves the removal of oxygen. During detrification, certain bacteria convert nitrates into nitrogen gas, ultimately depleting the oxygen levels in the environment. This process is typically observed in oxygen-deprived environments such as wetlands or waterlogged soils. By removing oxygen, detrification plays a crucial role in the nitrogen cycle and helps maintain the balance of nutrients in ecosystems.Rate this question:
- 5.
Mutualistic bacteria live where?
Correct Answer
on roots of plantsExplanation
Mutualistic bacteria live on the roots of plants. This symbiotic relationship benefits both the bacteria and the plants. The bacteria provide essential nutrients, such as nitrogen, to the plants, while the plants provide a habitat and nutrients for the bacteria. This mutualistic interaction helps the plants in nutrient uptake and growth, while the bacteria receive a stable environment and a source of food. This close association between mutualistic bacteria and plant roots is a common occurrence in nature and plays a crucial role in ecosystem functioning.Rate this question:
- 6.
Ammonification is the production of ammonia from organic molecules that contain ammonium. An example of these molecules could be:
Correct Answer
urea
proteins
nucleic acids
vitaminsExplanation
Ammonification is the process by which organic molecules containing ammonium are converted into ammonia. Urea, proteins, nucleic acids, and vitamins are all examples of organic molecules that can undergo ammonification. During this process, these molecules are broken down and ammonia is released. This ammonia can then be used by other organisms or converted into other forms of nitrogen.Rate this question:
- 7.
Ammonium to nitrite is
- A.
Oxidation
- B.
Reduction
Correct Answer
A. OxidationExplanation
Ammonium to nitrite is an oxidation process because it involves the loss of electrons. In this reaction, ammonium (NH4+) is converted into nitrite (NO2-), and during this conversion, the nitrogen atom in ammonium loses electrons and its oxidation state increases. Oxidation reactions typically involve the loss of electrons or an increase in oxidation state.Rate this question:
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- 8.
Nitrite to nitrate is
- A.
Oxidation
- B.
Reduction
Correct Answer
A. OxidationExplanation
Nitrite to nitrate is an oxidation process. In this reaction, nitrite (NO2-) is converted into nitrate (NO3-) by losing electrons. Oxidation involves the loss of electrons or an increase in the oxidation state of an atom. In the case of nitrite, the nitrogen atom has an oxidation state of +3, and after the reaction, it becomes +5 in nitrate. This indicates that the nitrogen atom has undergone oxidation.Rate this question:
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- 9.
When eutrophication occurs, there are more of this type of bacteria in the soil
Correct Answer
anaerobic denitrifyingExplanation
Eutrophication is a process where excessive nutrients, such as nitrogen and phosphorus, enter a body of water, leading to an overgrowth of algae. When this happens, the algae eventually die and sink to the bottom, where they are decomposed by bacteria. Anaerobic denitrifying bacteria thrive in low-oxygen environments and play a crucial role in the nitrogen cycle by converting nitrate into nitrogen gas, which is released back into the atmosphere. Therefore, when eutrophication occurs, there is an increase in anaerobic denitrifying bacteria in the soil as they help to break down the excess nutrients and restore balance to the ecosystem.Rate this question:
- 10.
Increased anaerobic denitrifying bacteria is a bad thing because
- A.
More nitrogen is converted to nitrates
- B.
More nitrates are converted to nitrogen
- C.
More ammonium is produced
- D.
More oxidation occurs
Correct Answer
B. More nitrates are converted to nitrogenExplanation
Increased conversion of nitrates to nitrogen by anaerobic denitrifying bacteria is considered a bad thing because it reduces the availability of nitrates, which are an essential nutrient for plants. Nitrates serve as a source of nitrogen for plant growth and productivity. When nitrates are converted to nitrogen, it becomes unavailable for plants, leading to nutrient deficiency and reduced plant growth. Therefore, an increase in this conversion can negatively impact agricultural productivity and ecosystem health.Rate this question:
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Jan 22, 2024Quiz Edited by
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Jan 19, 2010Quiz Created by
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