How has the nucleus in cells evolved?

Common parts of a cell

The cell is the building block of an organism, its smallest living unit. By definition, all cells have the following:

A cell membrane: As a barrier between the cell and its environment, the membrane provides structure, protection and control over the movement of materials in and out of the cell.Cytoplasm: This refers to the contents of the cell membrane excepting the nucleus. One of its main components is cytosol, a jelly-like substance which acts as protection and support for the remaining contents.DNA: Each cell contains genetic material. However, the way it is stored is one of the distinguishing factors between a eukaryote (a plant or animal cell for example) and a prokaryote (like a bacterium). These represent the two main types of cells. The former has a nucleus — for its DNA — as well as other organelles while the latter does not. Organelles are parts of a cell that have a specialised function and their own membranes.Nucleus

When a virus infects a host cell, it uses the cell's machinery to make copies of its own genetic material in a process called replication. finally, during the process of self-assembly, that protein shell and the copies of the virus's genetic material are assembled into new viruses.