Organelles such as mitochondria and the endoplasmic reticulum have membranes that compartmentalize reactions and other metabolic processes. To function properly, the organelles must move substances across their membranes. what is a feature shared by mitochondria and the endoplasmic reticulum that increases the efficiency of their basic functions?

The correct answer is - they both have highly folded membranes.

Explanation:

Organelles such as the endoplasmic reticulum, Golgi apparatus, and mitochondria have highly folded double membranes. This highly folded membrane provides the increased surface area in the organelle.

As the inner membrane of these organelles is the site for many chemical reactions the highly folded or layered membranes get more space for such reactions to occur due to increased surface area.