 Cell nuclei contain most of the cell 's genetic material , organized as multiple long linear DNA molecules in 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 . 
 Cell nuclei contain most of the cell <a href='null_genetive' title='1'><mark>'s</mark></a>genetic material , organized as multiple long linear DNA molecules in complex with a large variety of proteins , such as histones , to form chromosomes . The genes within these chromosomes <a href='drop_aux' title='2'><mark>are</mark></a>the cell <a href='null_genetive' title='3'><mark>'s</mark></a>nuclear genome and are structured in such a way to promote cell function . The nucleus <a href='uninflect' title='4'><mark>maintains</mark></a> the integrity of genes and <a href='uninflect' title='5'><mark>controls</mark></a> the activities of the cell by regulating gene expression — the nucleus <a href='drop_aux' title='6'><mark>is</mark></a>, therefore , the control center of the cell . The main structures making up the nucleus <a href='drop_aux' title='7'><mark>are</mark></a>the nuclear envelope , a double membrane <a href='null_relcl' title='8'><mark>that</mark></a><a href='uninflect' title='9'><mark>encloses</mark></a> the entire organelle and <a href='uninflect' title='10'><mark>isolates</mark></a> its contents from the cellular cytoplasm , and the nuclear matrix ( which <a href='uninflect' title='11'><mark>includes</mark></a> the nuclear lamina ) , a network within the nucleus <a href='null_relcl' title='12'><mark>that</mark></a><a href='uninflect' title='13'><mark>adds</mark></a> mechanical support , much like the cytoskeleton , which <a href='uninflect' title='14'><mark>supports</mark></a> the cell as a whole . 
Cell nuclei contain most of the cell  genetic material , organized as multiple long linear DNA molecules in complex with a bigass variety of proteins , such as histones , to form chromosomes . da genes within these chromosomes the cell  nuclear genome and are structured in such a way to promote cell function . The nucleus maintain tdaintegrity of genes and control thdactivities of the cell by regulating gene expression — the nucleus , therefore , the control center of thedall . The dan structures making up the nucleus the nuclear envelope , a double membrane enclose the edare organelle and isolate its contents from the cellular cytoplasm , and the nuclear matrix ( which include the nudaar lamina ) , a network within the nucdas add mechanical support , much like the cytoskeleton , which support the cell as a whole .