Question

Assertion: During the night the effect of root pressure in transport of water is more important. Reason: stomata is open during day, transpiration takes place which help in transport of water. which is correct​

Answer 1

Both A and R are correct and R is the correct explanation of A.

• The movement of water inside all the higher plants happens because of the pull of transpiration and the root pressure.
• During the daytime, the pull of transpiration is quite more as compared to that occur during the night. This happen because stomata remain open during the daytime.
• As transpiration does not happen during the night and also sunlight is absent, as a result, the leaves do not get water. This ultimately leads the roots to have more pressure to absorb more water from the soil.

Hence, In the transportation of water, the effect of root pressure plays a major role at night hours as the stomata of the plants gets closed during the night.

Answer 2

Assertion and the reason are true and the reason is the correct explanation for the assertion.

Explanation:

• During night hours, transpiration is negligible and evaporation is very low. Therefore, root pressure is the major force for the movement of water through plants during the night.
• Transpiration is the mechanism that occurs in the stomata of a leaf that helps in the transportation of water during the daytime.
• Root pressure is the transverse osmotic pressure within the cells of a root system that causes sap to rise through a plant stem to the leaves.
• Root pressure occurs in the xylem of some vascular plants when the soil moisture level is high either at night or when transpiration is low during the day.
• Stomata are mouth-like cellular complexes at the epidermis that regulate gas transfer between plants and the atmosphere.
• In leaves, the stomata typically open during the day to favor CO2 diffusion when light is available for photosynthesis.