A small opening in bark that allows gas exchange is called?

• A. Lenticels
• B. Bark
• C. Cambium
• D. Cortex

Answer: (A)

Lenticels are the small openings in the bark that allow gas exchange between living tissues inside the stem and the atmosphere. They consist of loosely arranged parenchyma cells with intercellular spaces, which create diffusion pathways for oxygen to enter and carbon dioxide to escape, supporting the metabolic needs of the tissues beneath the bark. The bark itself is the protective outer covering, the cambium is the growing cell layer between xylem and phloem, and the cortex is internal tissue in the stem—none of which are openings for gas exchange like lenticels.