Answer:
The bacteria found on roots, mainly on legumes, are related to the nitrogen cycle because nitrogen found in the environment is not usable by many species but because the bacteria can "fix" the nitrogen, it is usable by the plant which in turn it returned into the environment. 
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The slow rate at which diffusion occurs over large distances.
        
             
        
        
        
Answer:
Where's the full question?
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Answer:
Endonerium
Explanation:
The endoneurium (also called endoneurial channel, endoneurial sheath, endoneurial tube, or Henle's sheath) is a layer of delicate connective tissue around the myelin sheath of each myelinated nerve fiber in the peripheral nervous system. Its component cells are called endoneurial cells.The endoneuria with their enclosed nerve fibers are bundled into groups called nerve fascicles, each fascicle within its own protective sheath called a perineurium. In sufficiently large nerves multiple fascicles, each with its blood supply and fatty tissue, may be bundled within yet another sheath, the epineurium.