Which of the following molecules do plants primarily produce using nitrogen obtained through nitrogen fixation?

• A. Chlorophyll
• B. Amino acids
• C. Glucose
• D. Cellulose

Answer: (B)

Verified step by step guidance

1. Understand the concept of nitrogen fixation: Nitrogen fixation is the process by which certain bacteria convert atmospheric nitrogen (N₂) into ammonia (NH₃), which can be used by plants to synthesize organic molecules.
2. Recognize the role of nitrogen in biological molecules: Nitrogen is a key component of amino acids, which are the building blocks of proteins. It is also found in nucleotides, but not in molecules like glucose or cellulose, which are primarily composed of carbon, hydrogen, and oxygen.
3. Analyze the options provided: Chlorophyll contains nitrogen, but it is not the primary molecule produced using nitrogen fixation. Glucose and cellulose are carbohydrates and do not contain nitrogen. Amino acids, however, are directly synthesized using nitrogen obtained through nitrogen fixation.
4. Connect nitrogen fixation to plant metabolism: Plants absorb nitrogen in the form of ammonium (NH₄⁺) or nitrate (NO₃⁻) and use it to synthesize amino acids. These amino acids are then used to build proteins and other nitrogen-containing compounds.
5. Conclude that the correct answer is amino acids: Based on the role of nitrogen fixation and the composition of the molecules listed, amino acids are the primary molecules produced by plants using nitrogen obtained through nitrogen fixation.