NUCLEUS 

• Contains most of the DNA in an eukaryotic cell

• Ribosomes use the information from the DNA to make proteins

• The nucleus contains most of the cell’s genes and is usually the most conspicuous organelle

• The nuclear envelope encloses the nucleus, separating it from the cytoplasm

NUCLEAR MEMBRANE

•  Double membrane, each consists of a lipid bi-layer

• Pores regulate the entry and exit of molecules front he nucleus

• The shape of the nucleus is maintained by the nuclear lamina, composed of protein 

CHROMOSOMES 

• DNA is organized into discrete units called chromosomes

• Each chromosome is one long DNA molecule associated with proteins

• The DNA and proteins of chromosomes are together called chromatin

• When a cell prepares to divide, chromatin condensed to form discrete chromosomes

• The nucleolus is located within the nucleus and is the site of rRNA synthesis

RIBOSOMES 

• Ribosomes are complexes of ribosomal RNA and protein

• Ribosomes carry out protein synthesis in two locations - Cytosol (Free ribosomes) and On the outside of ER or nucleus envelope (bound ribosomes)