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.
Other plants benefit from N-fixing bacteria when the bacteria die and release nitrogen to the environment, or when the bacteria live in close association with the plant. In legumes and a few other plants, the bacteria live in small growths on the roots called nodules. Within these nodules, nitrogen fixation is done by the bacteria, and the NH3 they produce is absorbed by the plant. Nitrogen fixation by legumes is a partnership between a bacterium and a plant. Biological nitrogen fixation can take many forms in nature, including blue-green algae (a bacterium), lichens, and free-living soil bacteria.