In this procedure, the CS is paired with the US, but the US also occurs at other times. If this occurs, it is predicted that the US is likely to happen in the absence of the CS. In other words, the CS does not predict the US. In this case, conditioning fails and the CS does not come to elicit a CR.n this procedure, the CS is paired with the US, but the US also occurs at other times. If this occurs, it is predicted that the US is likely to happen in the absence of the CS. In other words, the CS does not predict the US. In this case, conditioning fails and the CS does not come to elicit a CR.
Nitrogen fixation is the process of nitrogen gas from the air  being turned into a compound in the soil by bacteria that live in  the root nodules of certain plants (legumes â¦).itrogen fixation which is the natural process of breaking down  nitrogen from atmosphere to ammonia NH3. It is done either  biologically or abiotically. This process is don â¦ e by bacteria.
The bacteria fix nitrogen by converting it to ammonia and nitrates which the plant can absorb and use to build its nitrogen containing molecules such as amino and nucleic acids. In return it offers some of its own sugars to the bacteria to cover their needs. It's a trade off between biologically usable nitrogen and sugar.