We know that plants are important to the ecosystem because they photosynthesize. Did you know that some plants are legumes and these are special because they have ROOT NODULES which are nitrogen fixers. These root nodules are little rooms where Rhizobium bacteria convert nitrogen gas into ammonium and then Nitrobacter bacterium in the soil converts ammonium into nitrates. Plants can absorb nitrates to make plant protein. When those plants are eaten by animals, then animals use the nitrogen to make animal protein. You can say that all the protein on your body (muscles, enzymes, hair, fingernail etc) was built from nitrogen which was fixed by Rhizobium at some point in time.
10 points
Only certain plants contain these root nodules...amongst them are bean plants and clover plants. Look at the roots of clover and draw a picture of root nodules.