∞ generated and posted on 2016.08.25 ∞
Double-layered membrane-associated structure containing the chromosomes of eukaryotic organisms, part of the endomembrane system.
The vast majority of DNA associated with eukaryotic cells is found in the nucleus, though additional DNA can be found in endosymbionts.
Figure legend: Wet mount of cell from purple onion as stained with iodine to bring out the cell nucleus. Note also the prominent cell walls.
In addition to an inner member and outer membrane, together forming the double membrane, the nucleus also possesses pores through which material passes from inside the nucleus into the cytoplasm. These materials include the messenger RNA that connects DNA with protein synthesis. Materials also can flow into the nucleus, including numerous proteins involved in chromosome structure and functioning.