Question

Which structure in a leaf is mainly responsible for gaseous exchange?

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

Hint:

Stomata = Gaseous exchange + Transpiration
Xylem = Water transport
Phloem = Food transport
Cuticle = Protection + Waterproofing

Answer 1

The Correct Option is B

Step 1: Understand the function of each structure.

• Xylem: Vascular tissue responsible for transport of water and minerals from roots to other parts of the plant.
• Stomata: Tiny pores present on the surface of leaves that allow gaseous exchange (oxygen and carbon dioxide) and transpiration.
• Phloem: Vascular tissue responsible for transport of food (sugars) from leaves to other parts of the plant.
• Cuticle: Waxy layer on the leaf surface that prevents water loss but also limits gaseous exchange.

Step 2: Identify the structure for gaseous exchange.
Stomata are the specialized structures that open and close to regulate the exchange of gases (CO₂ and O₂) between the leaf and the atmosphere. Final Answer: (B) Stomata