Give reasons for the following.
1. Transpirtation helps in ascent of sap.
2. Water column is maintained inside xylem vessels.
3. Intensity of light increases transpirtation rate.
4. Absorption of water from soil by root hair occurs by osmosis and not by diffusion.
Answers
Answer:
1) Evaporation of water molecules from the cells of a leaf creates a suction which pulls water from the xylem cells of roots. Thus, transpiration helps in the absorption and upward movement of water and minerals dissolved in it from roots to the leaves.
2)Water column in xylem vessels are constantly maintained due to cohesion and transportation pull theory. As the xylem vessels are connected to each other, it allows water to stay in a continuous column to the mesophyll cells from the root hairs. Lignin and cellulose of xylem have strongly adhered water.
3)Light intensity: The transpiration rate is increased due to the increase in light intensity. During daytime in the sunlight, the rate of transpiration is faster. This is because the stomata remains open to allow the inward diffusion of carbon dioxide for photosynthesis.
4)Both diffusion and osmosis are passive modes of transport. Absorption of water by a solid surface is called imbibition. ... The pressure gradient drives the osmotic transport of water from the soil into the xylem tissues of the roots. So, the correct answer is option C.
Hope this answer will help you
Mark me as Brainliest