Nucleus is a double-membraned organelle, present in the eukaryotic cells. It contains the genetic material and controls all the activities of the cell.
1) The nuclear membrane has pores which are the protein channels to allow the transfer of material from inside the nucleus to its outside, to the cytoplasm. These are referred to as nuclear pores.
2) Nucleolus is a dark coloured, round or slightly irregular structure which is attached to the chromatin (condenses to form chromosomes during cell division) at a specific region.