CO\(_2\) enters and O\(_2\) escapes from a leaf via which of the following structures?

• A. Stomata
• B. Xylem vessels
• C. Cuticle
• D. Phloem tubes

Answer: (A)

Verified step by step guidance

1. Understand the function of stomata: Stomata are small openings on the surface of leaves that allow for gas exchange. They facilitate the entry of CO\(_2\) for photosynthesis and the release of O\(_2\) as a byproduct.
2. Review the role of xylem vessels: Xylem vessels are specialized structures responsible for transporting water and minerals from the roots to the rest of the plant. They are not involved in gas exchange.
3. Examine the cuticle: The cuticle is a waxy layer covering the surface of leaves and stems. Its primary function is to prevent water loss, not to facilitate gas exchange.
4. Analyze the function of phloem tubes: Phloem tubes transport sugars and other organic compounds throughout the plant. They do not play a role in the exchange of gases like CO\(_2\) and O\(_2\).
5. Conclude that stomata are the correct structures for gas exchange, as they are specifically adapted to allow CO\(_2\) to enter and O\(_2\) to escape from the leaf.