The part of a plant cell that includes instructions for how to build and operate the cell is called the nucleus.

Here's why:

* DNA: The nucleus contains the cell's genetic material, DNA (deoxyribonucleic acid). DNA holds the instructions for building and maintaining the entire organism.

* Genes: DNA is organized into genes, which are specific segments of DNA that code for the production of proteins.

* Proteins: Proteins carry out a wide variety of functions within the cell, from building structures to catalyzing chemical reactions.

So, the nucleus is like the "control center" of the plant cell, holding the blueprint for the cell's activities.