Legumes, a type of plant, require Rhizobia, a type of soil bacteria, to survive since these organisms fix nitrogen during photosynthesis. Rhizobia use the legumes for food. What would most likely happen to the legume population if Rhizobia suddenly became extinct?
become extinct
learn to fix nitrogen
benefit in the long run
stay the same

The legume population would become extinct in future.  

•A bacterium found in soil, which assists in fixing nitrogen in nitrogenous plants is rhizobium.  

•It forms a symbiotic association with leguminous plants.  

•The rhizobium attaches with the leguminous plants roots and produces nodules.  

•These nodules assists in fixing atmospheric nitrogen and transform it into ammonia, which can be utilized by the plant for its development and growth.  

•In case, if rhizobium becomes extinct, then leguminous plants would fail to fix atmospheric nitrogen and would not be able to grow.  

Thus, with the extinction of rhizobium species, the leguminous plants will also get extinct in the long run.

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rhizobia is an important nitrogen fixing bacteria found in the soil to help grwo plants like legumes. rhizobia enter into a symbiotic relationship withe legumes

Explanation:

rhizobia and legumes coexist by entering into a symbiotic association.  rhizobia is a bacteria that fixes nitrogen molecules for the legumes and in return the legumes provide the bacteria with food and nutrition.

If rhizobia becomes extinct in the near future it would be difficult for plants like legumes to grow as they wouldn't get sufficient nitrogen and nitrogen is an important nutrition for the plant to grow and develop. Thus it can cause rapid depletion or death of plants that need rhizobia to fix nitrogen molecules for them.