What is Cell nucleus?
[[File:HeLa Hoechst 33258.jpg|thumb|300px|right|Cells in [[tissue culture]] [[Staining|stained]] for [[DNA]] with the blue Hoechst dye. The middle and right cells are in [[Cell division|interphase]], so their entire nuclei are labeled. On the left, a cell is going through [[mitosis]] and its DNA has condensed, ready for division]] [[File:Animal Cell.svg|thumb|right|280px|Diagram of a typical animal cell 1.[[Nucleolus]] 2.[[Nucleus]] 3.[[Ribosomes]] 4.[[Vesicle]] 5. rough [[endoplasmic reticulum]] 6.[[Golgi apparatus]] 7.[[Cytoskeleton]] 8. smooth [[endoplasmic reticulum]] 9.[[Mitochondrion]] 10.[[Vacuole]] 11.[[Cytosol]] 12.[[Lysosome]] 13.[[Centriole]] 14.[[Cell membrane]]]] [[File:Diagram human cell nucleus.svg|thumb|250px|right|The eukaryotic cell nucleus. Seen here are the [[ribosome]]-dotted [[cell membrane|double membranes]] of the nuclear envelope, the [[DNA]] complex, and the [[nucleolus]]]] The '''cell nucleus''' (plural: cell nuclei) contains the cell's [[genes]] and controls the cell's growth and reproduction. It has a double layered nuclear membrane round it. The nucleus is usually the most prominent [[organelle]] in a cell. The nucleus is small and round, and works as the cell's control center. It contains [[chromosome]]s which house the DNA. The [[human body]] contains billions of cells, most of which have a nucleus. All [[eukaryote]] [[organisms]] have nuclei in their cells, even the many eukaryotes that are single-celled. [[Bacteria]] and [[Archaea]], which are [[prokaryote]]s, are single-celled organisms of a different type and do not have nuclei. Cell nuclei were first found by [[Antonie van Leeuwenhoek]] in the [[17th century]]. The nucleus has a [[membrane]] around it but the things inside it do not. Inside it are many [[protein]]s, [[RNA]] molecules, chromosomes and the [[nucleolus]]. In the nucleolus [[ribosome]]s are put together. After being produced in the nucleolus, ribosomes are exported to the cytoplasm where they translate [[mRNA]] into pro