Why do nitrogen-fixation nodules contain large amounts of leghemoglobin?
A. It helps transport oxygen to the bacteria.
B. The nitrogenase enzyme interacts with the iron in the leghemoglobin.
C. It stimulates the Nod factors.
D. It prevents carbon dioxide from inhibiting the nitrogenase enzyme.
E. The leghemoglobin helps break the triple bond of N2.
Answer: A
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