Question

The transpiration and gaseous exchange in leaves takes place through

• A. Hair.
• B. Epidermis.
• C. Cuticle.
• D. Guard cells.
• E. Sweat gland.

Answer 1

Answer: (D)

Guard cells.

Stomata are the organs of transpiration which are present in the epidermis and their opening and closing are regulated by the change in the turgidity of guard cells. The opening of stomata caused by turgid guard cells permits gaseous exchange and transpiration. Leaf cuticle is protective covering on leaf epidermis and is composed of cutin, an insoluble heterogeneous lipid-polymer of long chain substituted aliphatic acids. Hence, it serves as water impervious layer to prevent water loss through transpiration.

So, the correct answer is option D.