The structure in the nucleus that is a storehouse for information needed by the cell to function is the chromatin.

Here's why:

* Chromatin is made up of DNA, which contains the genetic instructions for the cell. These instructions determine everything from the cell's shape and size to its metabolic processes.

* DNA is organized into structures called chromosomes, which are tightly coiled strands of chromatin.

* During cell division, the chromatin condenses into chromosomes to ensure that each daughter cell receives a complete set of genetic information.

So, the chromatin within the nucleus acts as a library holding the blueprints for the cell's operation.