The jelly-like material outside the nucleus but inside the cell membrane is called the cytoplasm.

Here's a breakdown:

* Cytoplasm: This is the gel-like substance that fills the cell and surrounds the nucleus. It's primarily composed of water, salts, and proteins.

* Nucleus: This is the control center of the cell, containing the cell's genetic material (DNA).

* Cell Membrane: This is the outer boundary of the cell, regulating what enters and exits.

The cytoplasm is a very active part of the cell, housing many important organelles (like mitochondria, ribosomes, and the endoplasmic reticulum) that carry out essential cellular functions.