Which organisms fix nitrogen into forms like ammonia A.Bacteria B.Humans C.Plants D.Algae?

A. Bacteria are the primary organisms that fix nitrogen into forms like ammonia. Certain bacteria, including those in the genera Rhizobium and Frankia, perform this process either in symbiotic relationships with plants or independently in the soil. While some algae also have the capability to fix nitrogen, it is predominantly bacteria that are recognized for this essential ecological function. Humans and plants do not fix nitrogen.