In order for plants to assimilate nitrogen directly into their system, the nitrogen must be in the form of nitrates. Nitrogen in the air and ammonia from decayed matter in the soil is converted to ammonium by decomposers and nitrogen-fixing bacteria. The ammonium is further nitrified to nitrates by nitrifying bacteria. Finally, the nitrates can then absorbed by the plants.
The primary source of stem thickening in plants is the vascular cambium. It is a plant tissue located between the phloem and the xylem and in the root of a vascular plant. It is the source of secondary growth or the radial growth of the stem of a plant.
Through these processes, plants obtain the carbon dioxide they need and living<span>organisms obtain the oxygen they need. They are also </span>necessary<span> to the energy exchange that </span>living things<span> need to survive. ... While </span>photosynthesis<span> requires energy and produces food, </span>cellular respiration<span> breaks down food and releases energy.</span>
