Question

You remove four fresh tobacco leaves of similar size and age. Leave "leaf 1" as it is, smear "leaf 2" with vaseline on the upper surface, "leaf 3" on the lower surface and "leaf 4" on both the surfaces. Hang the leaves for a few hours and you observe that leaf 1 wilts the most, leaf 2 has wilted, leaf 3 wilted less than leaf 2 and leaf 4 remains fresh. Which of the following conclusion is most logical?

• A. Tobacco leaf has more stomata on the upper surface
• B. Tobacco leaf has more stomata on the lower surface
• C. Stomata are equally distributed in upper and lower surfaces
• D. No conclusion on stomatal distribution can be drawn from this experiment

Answer 1

Answer: (A)

Tobacco leaf has more stomata on the upper surface

Transpiration is the loss of water in the form of water vapor from the parts of the plant. This takes with the help of stomata that are mostly present on the lower surface of leaves.

Leaf 1 is left as it is so it will undergo wilting.

Leaf 2 is smeared with vaseline on the upper surface and leaf 3 is smeared with vaseline on the lower surface. Hence leaf 2 will wilt more due to the presence of more stomata on the lower surface.

Leaf 4 will remain fresh due to the stomatal covering on both surfaces.

Thus, the correct answer is option B.