We have moved outside of the cell nucleus to see the nuclear membrane. The holes are minute pores that allow materials to pass between the nucleus and the outer regions of the cell. The chromosomes are contained within the nucleus.
Every complete cell has such a nucleus.
DNA remains within the nucleus of the cell. Part of the DNA uncoils from its chromosome packing and the two strands become separated for a portion of their length. One of them serves as a template upon which the mRNA is formed. The mRNA travels through the pores in the nuclear membrane into the cytoplasm of the cell where it is used as a template to create a specific protein.