It makes up chromosomes.
Stores genetic info
A plastid is like a specialized tool in a Swiss Army knife, with different types (like chloroplasts and chromoplasts) serving specific functions within a cell, similar to how different tools on a Swiss Army knife serve specific purposes.
A "nucleus" is found in every cell in the body and basically like the... overall commander of the cell It does not let in the nutrients that is the job of the Cell Membrane which is partially permeable. Post Script, there is quite a lot of cells in the body...