The cell nucleus is one of the largest organelles found in cells and also plays an important biological role. It composes about 10% of the total volume of the cell and is found near the center of eukaryotic cells. Its importance lies in its function as a storage site for DNA, our genetic material.
A monorail is a railway in which the track consists of a single rail. The term is also used to describe the beam of the system, or the vehicles traveling on such a beam or track.
mainline meaning, mainline definition | English Cobuild dictionary. mainline. 1 adj A mainline railway is a major railway between two important places. ...the first mainline railway to be built in Britain for almost a hundred years..., ...London's mainline stations.