Question

The number of stomata and epidermal cells in 1$m{m}^2$ leaf area in the lower epidermis of the leaves of X, Y and Z plants is given below. Arrange the plants in decreasing order of their stomatal index.

cells	Number of Stomata	Number of epidermal cells
X	30	150
Y	60	240
Z	90	400

• A. X, Y, Z
• B. Y, Z, X
• C. Z, Y, X
• D. Y, X, Z

Answer 1

Answer: (B)

Y, Z, X

Stomatal index (SI)$=\frac{S}{S+E}\times 100$

Cells	Number of Stomata	Number of epidermal cells	SI
X	30	150	16.6
Y	60	240	20.0
Z	90	400	18.3

So, the arrangement of plants in decreasing order of their stomatal index is Y, Z, X.