The most appropriate part of leaf epidermis in a dicot plant to observe stomata and guard cells would be on

1. Dorsal side

2. Ventral side on midrib

3. Veins

4. Any part on ventral but not midrib

The correct option is D

Any part on ventral but not midrib

The correct option is D.

Explanation of the Correct Option:

• The ventral side refers to the lower surface of the leaf, while the dorsal side refers to the upper surface of the leaf facing apical meristem.
• The dorsal side has more pigment than the ventral side in dicot leaves.
• The ventral side of the dicot leaf has more stomata surrounded by guard cells than the dorsal side to reduce the transpiration rate.
• The midrib is the vein present at the center of the leaf that does not contain any stomatal openings.

Explanation of Incorrect options:

Option A:

• The dorsal side or the upper side of the leaf has fewer stomata to reduce transpiration.

Option B:

• The midrib of the leaf does not contain stomata.

Option C:

• Veins do not have stomatal openings.

Therefore, the most appropriate part of the dicot leaf to observe stomata and guard cells would be the ventral side but not the midrib.