Old trees obtain `O_(2)` through

Options

A. Stomata
B. Lenticels
C. Leaf scars
D. All the above

Answer

**Step-by-Step Solution:**

1. **Understanding Gaseous Exchange in Trees:**
- Trees, like all plants, undergo gaseous exchange, which involves the intake of oxygen (O₂) and the release of carbon dioxide (CO₂) during the process of respiration.

2. **Identifying Structures Involved in Gaseous Exchange:**
- The primary structures in trees that facilitate gaseous exchange are stomata and lenticels.
- Stomata are small openings found mainly on the leaves, while lenticels are small pores found on the stems and branches of woody plants.

3. **Role of Stomata:**
- Stomata are crucial for the exchange of gases. They allow the intake of O₂ during respiration and the release of CO₂.
- They are the main sites for gas exchange in leaves, where photosynthesis and respiration occur.

4. **Role of Lenticels:**
- Lenticels also facilitate gas exchange, particularly in older trees where the bark has thickened.
- However, their primary role is more associated with the intake of CO₂ rather than O₂.

5. **Considering Leaf Scars:**
- Leaf scars are remnants of where leaves were attached to the stem and do not play a role in gaseous exchange.
- Therefore, they are not a method through which trees obtain oxygen.

6. **Conclusion:**
- Given the options provided (stomata, lenticels, leaf scars, and all of the above), the most accurate answer is that old trees obtain O₂ primarily through stomata.

**Final Answer:**
Old trees obtain O₂ through **stomata**.

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