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प्रश्न
Explain the mechanism of closing and opening of the stomata.
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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.
संबंधित प्रश्न
The process by which root hairs absorb water from the soil.
Multiple Choice Question:
Put a tick mark (✓) against the correct alternative in the following statement:
The root-hairs are suited for absorbing water from the soil because:
How does movement and absorption of water take place through the roots?
Choose the correct answer:
The water is translocated upwards from the roots through _____________
Name the following:
The solution outside the cell having lower solute concentration than the fluids.
Trace the pathway followed by water molecules from the time it enters a plant root to the time it escapes into the atmosphere from a leaf.
Minerals cannot be passively absorbed by the roots.
Identify labels x, y, z in the given figure of root showing different regions.
Which part of the root helps in maximum absorption of water and minerals?
Paheli uprooted a rose plant from the soil. Most of the root tips, with root hairs, got left behind in the soil. She planted it in a pot with new soil and watered it regularly. Will the plant grow or die? Give reason for your answer.
