Nucleus; nuclear; nucleic acid.
[Latin nucleus, inner part, kernel.]
In a cell, the nucleolus is a small dense spherical structure in the nucleus which disappears during cell division; the nucleoplasm is the substance of the cell nucleus; a nucleoprotein is a compound occurring in cells, a nucleic acid bonded to a protein. In biochemistry, nucleotides form the basic structural unit of nucleic acids such as DNA, and consist of phosphate groups attached to nucleosides, which consist of purine or pyrimidine bases linked to sugars. Nucleonics is the branch of science and technology concerned with atomic nuclei and nucleons (protons and neutrons), especially the exploitation of nuclear power; nucleosynthesis is the cosmic formation of atoms more complex than the hydrogen atom.