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.
Nitrogen-fixing bacteria. Nitrogen-fixing bacteria, microorganisms capable of transforming atmospheric nitrogen into fixed nitrogen (inorganic compounds usable by plants). More than 90 percent of all nitrogen fixation is effected by these organisms, which thus play an important role in the nitrogen cycle. Two kinds of nitrogen-fixing bacteria are recognized.