Question

Given below is the diagram of a stomatal apparatus. In which of the following all the four parts labelled as A, B, C and D are correctly identified?

• A. A- Epidermal cell, B- Subsidiary cell, C- Guard cell, D- Stomatal aperture
• B. A- Guard cell, B- Stomatal aperture, C- Subsidiary cell, D- Epidermal cell
• C. A- Epidermal cell, B- Guard cell, C- Stomatal aperture, D- Subsidiary cell
• D. A- Subsidiary cell, B- Epidermal cell, C- Guard cell, D- Stomatal aperture

Answer 1

Answer: (A)

A- Epidermal cell, B- Subsidiary cell, C- Guard cell, D- Stomatal aperture

Answer 2

Transpiration is loss of water in vapour form through the stomatal pores (Label C). The stomatal pore is regulated by guard cells (Label D). The stomatal pore, guard cells and surrounding 3 to 4 thin walled subsidiary cells (Label B), together constitute the stomatal apparatus. The stomatal apparatus is present in the epidermal layer (Label A). The guard cells contain stomata and in this respect are different from the epidermal cells.