Question

Lenticels permit the:

• A. Exchange of water between the outer atmosphere and internal tissue of the stem in most woody trees.
• B. Exchange of gases between the outer atmosphere and internal tissue of the stem in most woody trees.
• C. Exchange of heat between the outer atmosphere and internal tissue of the stem in most woody trees.
• D. Exchange of radiation between the outer atmosphere and internal tissue of the stem in most woody trees.

Hint:

Think of lenticels as the "stomata of the bark." Just as stomata allow leaves to breathe, lenticels allow the woody stem to breathe. Their function is gas exchange.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Lenticels are structures on woody stems and roots. This question concerns their main purpose.
Step 2: Detailed Explanation:


Young stems use stomata for gas exchange. Secondary growth replaces the epidermis with impermeable periderm (bark).

Lenticels, specialized pores, facilitate respiration for living cells within the woody stem.

A lenticel is porous tissue with cells containing large intercellular spaces, breaching the bark's cork layer.

Their key function is direct gas exchange (oxygen, carbon dioxide, water vapor) between the stem's inner tissues and the atmosphere.

They don't primarily exchange liquid water (A), heat (C), or radiation (D). While some water vapor escapes, their main function is respiratory gas exchange.

Step 3: Final Answer:
Lenticels enable gas exchange between the atmosphere and the stem's internal tissues.