Biology / Unit 9 Bio 1969 short lesson, about 20 seconds
Nitrogen-Fixation Mutualism
Captions available
The idea
Rhizobia bacteria fix atmospheric nitrogen inside legume root nodules, trading fixed nitrogen for photosynthetic sugars in a mutually beneficial relationship.
In practice
Soybean root nodules house rhizobia that supply the plant with usable nitrogen, while the plant supplies the bacteria with carbohydrates.
Where people slip
Do not credit the legume with fixing nitrogen— the plant cannot fix nitrogen itself; only the bacterial partner carries the enzyme machinery.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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