Nucleus

The most important and visible part of a cell is nucleus. It is present in the centre of the animal cell but due to presence of large central vacuole, it is pushed to one side in the plant cell.

Structure

Its structure contain various component parts e.g.

•         i.            Nuclear Membrane:

The outer most covering of nucleus is called nucleus membrane. It is a double membrane and also pores are present in it.

•       ii.            Nucleoplasm:

The granular matrix present inside cell is called Nucleoplasm.

•     iii.            Nucleoli:

In the Nucleoplasm, one or more nucleoli are present. These are usually visible as dark spots and are responsible for the formation of ribosomal RNA.

•      iv.            Chromosomes:

Chromosomes or genetic material is also present in Nucleoplasm in the form of chromatin (thread like structures).

Chromosomes are made up of Deoxyribonucleic acid (DNA) and histone proteins.

DNA contains the message for the synthesis of cellular proteins. This message is read by messenger RNA which carries it to ribosome for the protein synthesis.