What is the role of the nucleus?

The nucleus is the most important organelle of the cell and acts like a blueprint for how all the cells in your body function. The nucleus also acts as a vault to hold the DNA securely.
The main function of the nucleus is to contain the genetic material. This includes DNA which controls the cell’s activities by holding the instructions for protein synthesis. The subfunctions of the different parts of the nucleus are described below.
Nuclear pores
-Small channels around the nuclear envelope that allow substances such as RNA to enter and leave the nucleus.
-Nuclear pore complexes are proteins in the nuclear pore that controls which molecules can go in and out
-Molecules entering the nucleus are nuclear and ribosomal proteins
-Molecules leaving the nucleus are mRNAs and ribosomal subunits
Nuclear envelope 
-Made up of a membrane phospholipid bilayer: outer and inner membrane
-It encloses the nucleoplasm
-Helps maintain shape of nucleus
-The nuclear envelope is connected to the endoplasmic reticulum (ER)
-The internal compartment of the envelope in continuous with the lumen of ER
Nucleoplasm
-Gel like material that chromatin is stored in
-Chromatin is the DNA wrapped around proteins
Nucleolus 
-On a microscope, it appears as a dark part of a nucleus 
-Ribosome synthesis takes place here