Question

Given ahead is the diagram of an experimental set up to study the process of transpiration in plants. Study the same and then answer the questions that follow:

(a) Is the experimental leaf a monocot or a dicot? Give a reason to support your answer.
(b) Why are glass slides placed over the dry cobalt chloride papers?
(c) After about half an hour what change, if any, would you expect to find in the cobalt chloride paper placed on the dorsal and ventral sides of the leaf? Give a reason to support your answer.

<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> [Review Questions - Pg No.66 - Skill Type - 3]

Answer 1

(a) Stomata are minute openings in the epidermal layer of leaves. A stomata is surrounded by two bean-shaped guard cells. More transpiration occurs from the undersurface of a dicot leaf. There are more stomatal openings on the undersurface of a dicot leaf and therefore, more transpiration occurs from the undersurface.
(b) Glass slides are placed over the dry cobalt chloride papers so as to retain the strips in their position.
(c)

After about half an hour we observe that,

1. The water vapour condensing on its inner walls.

2. The second bell jar (B) would also show a similar condensation and at the same time, the initially blue cobalt chloride paper in it would turn pink.