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Showing results for how pull help in transpiration of water in plant
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Answer:
Transpiration pull model of water transport:
Transpiration in the daytime causes water loss from leaf cells like guard cells and epidermal cells. This creates a situation where these cells become flaccid and hence start absorbing water from the xylem tubes. This creates a negative pressure which causes water to rise through the xylem. Transpiration is supported by a positive root pressure.
Factors affecting transpiration are :
1. Temperature
2. Humidity
3. Light
4. Wind speed
5. Location of stomata
6. Number and distribution of stomata.
ANSWER-We all have observed tiny droplets on the leaf surface and on the margins of the leaves. Have you ever questioned yourself as to why these water droplets are formed on the leaves?
The dewdrops or the tiny water droplets formed on the leaves are the vapours, which are excreted by the leaves. It is just like we excrete waste, which includes both toxins and unwanted useful materials. These tiny water droplets are the extra amount of water excreted from the plant.
A process in which the moisture and other gaseous wastes are excreted through the stomata of the leaf, lenticels of the stem and fruits are termed as Transpiration.In this process, loss of water in the form of vapours through leaves are observed. This biological process is carried out in all higher plants and trees as their stems are surrounded by bundles of fine tubes, which are made from a woody material known as xylem.
Transpiration pull is also referred as suction force and this force is used to draw the water in an upward direction from the roots to the leaves. The amount of water received by the leaves are used for the photosynthesis and the excess amount of water is released into the atmosphere in the form of vapours through the openings in the leaves known as stomata.
The pressure created by transpiration pull applies a force on the combined water molecules and helps them to move in an upward direction into the mesophyll.
The mechanism involved in this biological process is based on the upward movement of water from the tip of the root to the aerial parts of the plant body which is called ascent of sap. During transpiration, a negative hydrostatic pressure is generated in the mesophyll cells to draw water from the roots to the veins of the leaves.
Explanation: I hope it's helpful.
