The feature common to both cellulose and sugar is that they are both carbohydrates.

Here's why:

* Cellulose is a complex carbohydrate made up of long chains of glucose molecules. It is a structural component of plant cell walls.

* Sugar is a simpler carbohydrate, typically referring to simple sugars like glucose, fructose, and sucrose. Sugars are a source of energy for living organisms.

Both cellulose and sugar are made up of carbon, hydrogen, and oxygen atoms, and are classified as carbohydrates.