What is within a nucleus of a cell?
Cell nucleus
Cell nuclei contain most of the cell's genetic material, organized as multiple long linear DNA molecules in a complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these chromosomes are the cell's nuclear genome and are structured in such a way to promote cell function. The nucleus maintains the integrity of genes and controls the activities of the cell by regulating gene expression—the nucleus is, therefore, the control center of the cell. The main structures making up the nucleus are the nuclear envelope, a double membrane that encloses the entire organelle and isolates its contents from the cellular cytoplasm, and the nuclear matrix (which includes the nuclear lamina), a network within the nucleus that adds mechanical support, much like the cytoskeleton, which supports the cell as a whole.
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.