Biology
Given below is a figure of a 'probable pathway of water through leaf cells during transpiration'. Before transpiration, certain processes occur in the cells like imbibition, evaporation, osmosis, diffusion, etc.
What will be the correct sequence for the processes A, B, C and D mentioned in the figure ?
- Imbibition, Osmosis, Diffusion, Evaporation
- Diffusion, Evaporation, Imbibition, Osmosis
- Evaporation, Diffusion, Osmosis, Imbibition
- Osmosis, Imbibition, Evaporation, Diffusion.
Answer
Osmosis, Imbibition, Evaporation, Diffusion.
Reason — First, a small proportion of water enters the cells by osmosis. Then most of the water moves along the cell walls by imbibition. From the cell walls, water evaporates into the intercellular spaces by evaporation. Finally, the water vapour moves out of the leaf into the outside air by diffusion.
Related Questions
Hydathodes are located on:
- At the petiole
- Upper surface of leaves
- Lower surface of leaves
- Margins of leaves
When guard cells are flaccid, the stoma must be:
- Open
- Neither open nor closed
- Closed
- None of these
A certain process called "Guttation' occurs from the leaves of herbaceous plants.
(i) The exudate released during the process is water without mineral salts.
(ii) Guttation occurs when the 'rate of absorption' exceeds the 'rate of transpiration'.
(iii) It happens through the hydathodes of the leaves plants growing in warm humid conditions only.
(iv) Guttation is a kind of exudation which usually occurs during summer afternoons.
Which of the above statements with respect to this process are correct ?
- (i) and (ii)
- (ii) and (iii)
- (iii) and (iv)
- (iv) and (i)
Assertion (A): Lenticels allow diffusion of gases for respiration.
Reason (R): Lenticels are located on the surface of older woody stems. They close during night time and open during the day for the process of transpiration.
- Both A and R are True
- Both A and R are False
- A is True and R is False.
- A is False and R is True.