Question

Dumb-bell shaped guard cells are seen in

• A. Wheat
• B. Mango
• C. Cucumber
• D. Pongamia

Hint:

Grasses = Monocots = Dumb-bell shaped guard cells.
Dicots = Kidney/Bean-shaped guard cells.
Identifying the taxonomic family (Poaceae) helps solve stomatal questions instantly.

Answer 1

The Correct Option is A

Step 1: Split the plants into monocots and dicots.
Mango, Cucumber and Pongamia are all dicotyledonous plants, while Wheat belongs to the grass family, Poaceae, a monocot.
Step 2: Recall the guard cell shape rule for each group.
Dicot guard cells are shaped like a kidney or bean, bulging in the middle and thin at the ends, this is the shape seen in Mango, Cucumber and Pongamia.
Step 3: Apply the rule to grasses.
Grasses like Wheat instead have narrow, dumb-bell shaped guard cells, thick at the two ends and thin in the middle, a shape unique to Poaceae among common flowering plants.
Final answer: Option 1, Wheat shows the dumb-bell shaped guard cells.