History of Cell nucleus

	Revision 5 . . (edit) December 1, 2001 2:57 am by Magnus Manske
	Revision 4 . . (edit) December 1, 2001 2:53 am by Magnus Manske
	Revision 3 . . December 1, 2001 2:50 am by Magnus Manske [+image]
	Revision 2 . . (edit) December 1, 2001 2:46 am by Magnus Manske [From [[nucleus]]]
	Revision 1 . . August 31, 2001 8:30 am by (logged).186.19.xxx [*currently there's "cell nucleus" content in "nucleus". Refactor at will.]

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Difference (from prior major revision) (minor diff, author diff)

Changed: 1c1

The cell nucleus is an organelle within an eukaryotic cell. It has two main functions:

The cell nucleus is an organelle within an eukaryotic cell. Its has two main functions :

Changed: 3c3

* to store information needed for when the cell divides

* to store information needed for when the cell divides?

Changed: 5c5

The nucleus controls reactions by controlling the formation of proteins and enzymes.

The nucleus controls reactions by controlling the formation of proteins and enzymes. It is also the place where the transcription of genes and mRNA splicing occur.

Changed: 7c7

Structure

Structure

Changed: 9c9,14

The nucleus varies in diameter from 10 to 20 micrometres. It is surrounded by a double membrane forming the nuclear envelope, about 30 nm wide. This selectively allows molecules to enter and leave the nucleus, and separates chemical reactions taking place in cytoplasm from reactions happening within the nucleus. The outer membrane has ribosomes. The inner and outer membrane fuse at regular spaces, forming nuclear pores.

http://www.nupedia.com/newsystem/upload_file/871/nucleus_ER.png Drawing of nucleus and the endoplasmic reticulum. (1) Nuclear envelope. (2) Ribosomes. (3) Nuclear pore complexes. (4) Nucleolus. (5) Chromatin. (6) Nucleus. (7) Endoplasmic reticulum. (8) Nucleoplasm?. The whole structure is surrounded by cytoplasm. (Drawing is based on ER images.) Image from Nupedia server.

Changed: 11c16,18

Similar to the cytoplasm of a cell, the nucleus contains nucleoplasm? - a highly viscous liquid containing the chromosomes and nucleoli. Chromosones contain information encoded in DNA attached to proteins called histones and are usually arranged in to a dense network called chromatin. Nucleoli are granular structures which make rionucleic-DNA (rDNA) and put together proteins.

The nucleus varies in diameter from 10 to 20 micrometres. It is surrounded by a double membrane forming the nuclear envelope, about 30 nm wide. This selectively allows molecules to enter and leave the nucleus, and separates chemical reactions taking place in cytoplasm from reactions happening within the nucleus. The outer membrane has ribosomes. The inner and outer membrane fuse at regular spaces, forming nuclear pores. Similar to the cytoplasm of a cell, the nucleus contains nucleoplasm? - a highly viscous liquid containing the chromosomes and nucleoli. Chromosones contain information encoded in DNA attached to proteins called histones and are usually arranged in to a dense network called chromatin. Nucleoli are granular structures which make ribonucleic DNA (rDNA?) and assemble it with proteins.