Advertisements
Advertisements
प्रश्न
Explain the mechanism of closing and opening of the stomata.
Explain the mechanism of stomatal respiration with the help of a labelled diagram.
Advertisements
उत्तर
The closing and opening of the stomata depends on the turgidity of the guard cells. Each guard
cell has a thicker wall on the side facing the stoma and a thin wall on the opposite side. Guard cells contain chloroplasts. As a result of the synthesis of glucose during photosynthesis and some other chemical changes, the osmotic pressure of the contents of the guard cells increases and they absorb more water from the neighbouring cells, thus becoming turgid. Due to turgor, the guard cells become more arched outwards and the aperture between them widens, thereby opening the stoma.
At night or when there is shortage of water in the leaf, the guard cells turn flaccid and their inner rigid walls become straight, thus closing the stomatal aperture.
APPEARS IN
संबंधित प्रश्न
Correct the following statement by changing the underlined word.
Xylem transports starch from the leaves to all parts of the plant body.
Differentiate between the following:
Guttation and bleeding
Choose the correct answer:
The water is translocated upwards from the roots through _____________
Mention whether the following statement is true (T) or false (F) and give explanation in support of your answer.
Dry seeds when submerged in water swell up due to endosmosis.
Study the experimental setup in the figure and then answer the question that follow.
Explain the phenomenon mention in question 8.1 .
Differentiate between the following
Permeable and Semi-permeable membrane.
A thin strip of epidermal cells from the fleshy scales of an onion bulb was examined in a drop of water, under a microscope. All the epidermal cells looked alike and the figure alongside represents one of them. The thin strip was then transferred to a drop of strong sugar solution and re-examined under the microscope after about five minutes.
(i) Make a sketch of one of the epidermal cells, as it might appear after immersion in a strong sugar solution. Label any two parts which have undergone a change.
(ii) Give the scientific term for the change shown in Q.(i) above.
(iii) What would you do to bring this cell back to its original condition?
(iv) Give the scientific term used for the recovery of the cell as a result of the step taken in Q.(iii) above.
Give Technical Term for the following.
Phenomenon of absorption of water by surface attraction.
Inner layer of root hair is made up of ______.
From which type of cells, root hair is originated
