👉 Fenestellid, also known as windowed cells or cell nuclei, are a type of biological structure that is important in many forms of plant and animal tissue. They are typically found at the base or center of a cell, where they are surrounded by other structures called endoplasmic reticulum (ER) membranes. Fenestellid cells can be classified into two main types: nuclear fenestellids and cytoplasmic fenestellids. Nuclear fenest