Final answer:
The unsuberized cells in the outer bark that facilitate gas exchange in woody plants are known as lenticels. They are essential for delivering oxygen to the plant cells and enabling respiration.
Step-by-step explanation:
The unsuberized cells in the outer bark which allow gas exchange to continue in the stem are called lenticels. These structures provide oxygen to the living and metabolically active cells of the cortex, xylem, and phloem. In woody plants, the cork cambium produces cork cells that form the protective bark layer with suberin to repel water. While the main function of bark is to protect the plant and reduce water loss, lenticels are crucial for enabling the exchange of gases with the surrounding atmosphere. These adaptations are essential for the survival and growth of woody plants.