They will attract each other together
Answer:
Stem cells.
Explanation:
Stem cells are the undifferentiated and unspecialized cells. These cells have the ability to divide for indefinite periods. Due to their ability to divide, these cells can give rise to specialized cells. Therefore, the cells present in the mucosal surface of the gastrointestinal tract that has the ability to give rise to specialized cells are stem cells. These cells are required to replace the damaged cells with the new functional cells.
Nitrogen fixation is the process by which nitrogen is taken from its relatively inert molecular form (N2) in the atmosphere and converted into nitrogen compounds useful for other chemical processes (such as, notably, ammonia, nitrate and nitrogen dioxide).
Nitrogen fixation is performed naturally by certain types of anaerobic bacteria. Legumes such as clover contain symbiotic bacteria of this type within nodules in their root systems, producing nitrogen compounds that help to fertilize the soil. See George Washington Carver.
Nitrogen can also be artificially fixed for use as fertilizer or in other industrial processes. The most popular method is by the Haber process. Artificial fertilizer production has achieved such scale that it is now the largest source of fixed nitrogen in the Earth's ecosystem.
(This is the definition from the http://encyclopedia.kids.net.au/page/ni/Nitrogen_fixation website)
It is the Watt per square meter, or W/m2.
