The cell nucleus is a membrane bound structure that contains the cell s hereditary information and controls the cell s growth and reproduction. It is the command center of a eukaryotic cell and is commonly the most prominent organelle in a cell.
The cell nucleus is bound by a double membrane called the nuclear envelope. This membrane separates the contents of the nucleus from the cytoplasm.
The nucleus is the organelle which houses chromosomes. Chromosomes consist of DNA , which contains heredity information and instructions for cell growth, development, and reproduction. When a cell is "resting" i.e. not dividing , the chromosomes are organized into long entangled structures called chromatin and not into individual chromosomes as we typically think of them.
Nucleoplasm is the gelatinous substance within the nuclear envelope. Also called karyoplasm, this semi-aqueous material is similar to cytoplasm and is composed mainly of water with dissolved salts, enzymes, and organic molecules suspended within.
Contained within the nucleus is a dense, membrane-less structure composed of RNA and proteins called the nucleolus. The nucleolus contains nucleolar organizers, which are parts of chromosomes with the genes for ribosome synthesis on them. The nucleolus helps to synthesize ribosomes by transcribing and assembling ribosomal RNA subunits. These subunits join together to form a ribosome during protein synthesis.
2017-11-12 LGN Dynamite 3-3 tie vs. FC Somers Benfica - Dauer: 1:20:15
Phacoemulsification - how to hold the nucleus : Pradip Mohanta - Dauer: 6:56