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Question 1:

Which process involves the conversion of atmospheric nitrogen into a usable form by plants?

A) Nitrification
B) Denitrification
C) Nitrogen fixation
D) Ammonification

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Explanation: The correct answer is C) Nitrogen fixation. Nitrogen fixation is the process by which atmospheric nitrogen (N2) is converted into a usable form, such as ammonia (NH3) or nitrate (NO3-), by certain bacteria and cyanobacteria. This process is essential for making nitrogen available for plants and is an important part of the nutrient cycle.

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Question 2:

Which process involves the release of phosphorus from organic matter back into the environment?

A) Assimilation
B) Mineralization
C) Weathering
D) Eutrophication

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Explanation: The correct answer is B) Mineralization. Mineralization, also known as decomposition, is the process by which organic matter, such as dead plants and animals, is broken down by decomposers (e.g., bacteria and fungi) into inorganic forms, including nutrients like phosphorus. These inorganic nutrients can then be taken up by plants and reused in the ecosystem.

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Question 3:

Which nutrient is a key component of nucleic acids, proteins, and ATP?

A) Nitrogen
B) Phosphorus
C) Carbon
D) Oxygen

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Explanation: The correct answer is A) Nitrogen. Nitrogen is an essential nutrient for living organisms, as it is a key component of nucleic acids (DNA, RNA), proteins, and ATP (adenosine triphosphate), which is the primary energy currency in cells. Nitrogen is obtained by plants through nitrogen fixation, and it cycles through various forms in the environment.

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Question 4:

Which process involves the uptake of inorganic nutrients by plant roots?

A) Assimilation
B) Nitrification
C) Ammonification
D) Absorption

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Explanation: The correct answer is D) Absorption. Absorption refers to the process by which plant roots take up inorganic nutrients, including nitrogen, phosphorus, and other essential elements, from the soil. These nutrients are then used by the plant for growth and metabolism.

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Question 5:

Which process involves the release of carbon dioxide back into the atmosphere by organisms?

A) Photosynthesis
B) Respiration
C) Nitrogen fixation
D) Denitrification

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Explanation: The correct answer is B) Respiration. Respiration is the process by which organisms, including plants, animals, and microorganisms, release energy from organic compounds (such as glucose) to fuel their metabolic activities. As a result of respiration, carbon dioxide is produced and released back into the atmosphere as a waste product.