The nucleus of a cell contains chromatin (a complex of DNA and histone
proteins) which is the genetic material of the cell
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Present in all eukaryotic cells, the nucleus is relatively large and separated
from the cytoplasm by a double membrane (the nuclear envelope) which
has many pores
Nuclear pores are important channels for allowing mRNA and ribosomes to
travel out of the nucleus, as well as allowing enzymes (eg. DNA polymerases)
and signalling molecules to travel in
The nucleus contains chromatin (the material from which chromosomes are
made)
Usually, at least one or more darkly stained regions can be observed – these
regions are individually termed ‘nucleolus’ and are the sites of ribosome
production
Function:
Nucleus is a membrane bound structure that carries the genes, structures that contain the
cell's hereditary information and regulates controls the cell's growth, reproduction and
metabolism. Nucleus is present in all eukaryotic cells, they may be absent in few cells like
the mammalian RBCs. Nucleoli are small bodies often seen within the nucleus. The gel-like
matrix in which the nuclear components are suspended is the nucleoplasm.
Size:
The nucleus is overall almost 5-10 micrometres in diameter in many multicellular organisms,
and the most prominent organelle in the cell.
Structure:
The shape of the nucleus is mostly round, it may be oval, disc shaped depending on the type
of cell. It is the command centre of a eukaryotic cell. The nuclear envelope is a double
membrane that separates the nucleus from the cytoplasm.