Here's why:

* Cork cells are dead cells: They are part of the protective outer layer of trees called bark.

* Loss of organelles: During the process of becoming cork, the cells lose their nucleus, cytoplasm, and other organelles.

* Suberin deposition: Cork cells are filled with a waxy substance called suberin, which makes them waterproof and resistant to decay. This process also results in the loss of the nucleus and other cell components.

While they lack a nucleus, cork cells still play an important role in protecting the tree from damage, pests, and water loss.