The setup in the figure concludes which of the transportation method in plants?
a. Transpiration pull. b. Stem pressure
.
c. Root pressure. d. Root transfer system.
Answers
Explanation:
)
Transpiration is a process that involves loss of water vapour through the stomata of plants. Transpiration is thought to be a 'necessary cost or evil' to allow the plant to absorb water from the soil. It is an inevitable process.
Turgidity, or turgor pressure, refers to the water content of cells and how this lends structural support to the plant. When cells absorb water, the vacuoles fill up and the cytoplasm increases, pushing against the cell membranes, which in turn push against the rigid cell walls. This makes the cells rigid, or turgid.
Transpiration is important in plants for three major reasons:
Cooling of the plant: the loss of water vapour from the plant cools down the plant when the weather is very hot.
The transpirational pull: when the plant loses water through transpiration from the leaves, water and mineral salts from the stem and roots moves, or is `pulled', upwards into the leaves. Water and is therefore taken up from the soil by osmosis and finally exits the plants through the stomata.
Plant structure: young plants or plants without woody stems require water for structural support. Transpiration helps maintain the turgidity in plants.
Transpirational pull: results from the evaporation of water from the surfaces of the mesophyll layer in the leaf to the atmosphere, through the stomata. Evaporation of water from the leaves surface causes a negative pressure (suction force) in the xylem that pulls water from the roots and soil. This results in water being drawn up the xylem vessel.
Transpirational pull draws water from the roots to the leaves because of the effects of capillary action. The primary forces that create the capillary action are adhesion and cohesion. Adhesion is the attraction that occurs between water and the surface of the xylem, and cohesion is the attraction between water molecules.
We will revisit transpirational pull and capillarity later in the chapter when we examine how water is transported in the plant.
Answer:
The setup in the figure concludes which of the transportation method in plants?
a. Transpiration pull
c. Root pressure
b. Stem pressure d. Root transfer system
Explanation:
The setup in the figure concludes which of the transportation method in plants?
a. Transpiration pull
c. Root pressure
b. Stem pressure d. Root transfer system