(a)[3]
Identify the processes occurring at H, J and K.
(b)[2]
Suggest the advantages that legumes gain from having Rhizobium living in their roots.
Biology 9700 · AS & A Level · Testing for biological molecules
Testing for biological molecules — practice question
Many legume species live in nitrate-poor tropical soils. Some are large trees, for example the flamboyant tree, Delonix regia. Bacteria in the genus Rhizobium inhabit swollen sections on legume roots. These swellings are called root nodules. A student traced nitrogen cycling in an area containing many flamboyant trees. Fig. 6.1 shows an overview of the nitrogen flow in the area.