Question

Which is not part of stomatal apparatus?

• A. Guard cells
• B. Subsidiary cells
• C. Stomatal pore
• D. Cuticle

Hint:

Stomatal apparatus = Stomatal pore + Guard cells + Subsidiary cells. Cuticle is a protective epidermal layer and not a component of the apparatus.

Answer 1

The Correct Option is D

Concept: The stomatal apparatus is a specialized structure present in the epidermis of leaves. It regulates gaseous exchange and transpiration. A typical stomatal apparatus consists of a pore and associated cells that help control opening and closing.

Step 1: Identify the components of stomatal apparatus. A stomatal apparatus consists of:
• Stomatal pore
• Two guard cells
• Subsidiary cells (in many plants) These components collectively regulate gas exchange.

Step 2: Analyze each option. Guard cells are essential components. Subsidiary cells are associated cells surrounding guard cells. Stomatal pore is the opening through which gaseous exchange occurs. Cuticle is a waxy protective covering present on the epidermis and is not considered a component of the stomatal apparatus.

Step 3: Conclude. Therefore, cuticle is not a part of the stomatal apparatus. \[ \boxed{\text{Cuticle}} \] Hence, the correct answer is \[ \boxed{(D)\ \text{Cuticle}} \]