Cell nucleus
The nucleus is the largest cellular organelle in animal cells.
In mammalian cells, the average diameter of the nucleus is approximately 6 micrometres (µm), which occupies about 10% of the total cell volume. The viscous liquid within it is called nucleoplasm (or karyolymph), and is similar in composition to the cytosol found outside the nucleus. It appears as a dense, roughly spherical or irregular organelle. The composition by dry weight of the nucleus is approximately: DNA 9%, RNA 1%, Histone Protein 11%, Residual Protein 14%, Acidic Proteins 65%.
Syllable
The "nucleus" is usually the vowel in the middle of a syllable. The "onset" is the sound or sounds occurring before the nucleus, and the "coda" (literally 'tail') is the sound or sounds that follow the nucleus. They are sometimes collectively known as the "shell". The term "rime" covers the nucleus plus coda. In the one-syllable English word "cat", the nucleus is "a" (the sound that can be shouted or sung on its own), the onset "c", the coda "t", and the rime "at". This syllable can be abstracted as a "consonant-vowel-consonant" syllable, abbreviated "CVC". Languages vary greatly in the restrictions on the sounds making up the onset, nucleus and coda of a syllable, according to what is termed a language's phonotactics.