Question

Stomata are mostly present on the

• A. upper surface of the leaf.
• B. lower surface of the leaf.
• C. tip of the leaf.
• D. point of attachment of the leaf to its petiole.

Answer 1

The correct option is B

lower surface of the leaf.

The correct option is B.

Explanation of the correct answer:

• Stomata are pores that control the rate of gas exchange and are found in the epidermis of leaves, stems, and other organs.
• If the stomata are present on the plant's lower surface, they will be less exposed to the sun and more shielded from the breeze.
• Transpiration is the water loss through stomata which will be enhanced if more stomata are present on the upper surface due to exposure to the sunlight. Hence, the lower surface has more stomata to prevent excessive water loss.

Explanation of the incorrect options:

Option A:

• Dicot leaves are held horizontally, causing the upper epidermis to receive direct illumination, so fewer stomata are present.

Option C:

• There are fewer stomata present on the leaf tip.

Option D:

• There are no stomata present on the attachment site.

Therefore, the stomata are mostly present on the lower surface of the leaf.