• # question_answer 121) Which one of the following mineral elements plays an important role in biological nitrogen fixation? A)  Copper      B)  ManganeseC)  Zinc        D)  Molybdenum

Molybdenum is a component of nitrogenase and nitrate reductase involved during${{N}_{2}}$fixation. Copper is essential for photosynthesis and respiration. Zinc is involved in synthesis of auxin. Manganese is activator of enzymes involved in nitrogen metabolism.