Short Answer Type
Long Answer TypeShort Answer TypeWith the help of well-labelled diagrams, describe the process of plasmolysis in plants, giving appropriate examples.
(b) Explain what will happen to a plant cell if it is kept in a solution having higher water potential.
Long Answer TypeDiscuss the factors responsible for ascent of xylem sap in plants.
The transpirational pull is mainly responsible for the ascent of xylem sap in plants.
This ascent of water is facilitated by the following physical factors:
i. Cohesion - It is the mutual attraction between water molecules
ii. Surface tension - It is responsible for the greater attraction between water molecules in liquid phase than in gaseous phase.
ii. Adhesion - Attraction of water molecules to polar surfaces like the tracheary elements.
iv. Capillarity -Ability of water to rise in thin tubes
These physical properties give water high tensile strength, i.e., an ability to resist a pulling force and high capillarity, i.e., the ability to rise in thin tubes. The thin tubes of xylem work like capillary tubes.
Multiple Choice QuestionsWater vapour comes out from the plant leaf through stomatal opening. through the same stomatal opening. carbon dioxide diffuses into the plant during photosynthesis. Reason out the above statements using the following options
Both processes can happen together because the diffusion coefficient of water and CO2 is different
The above processes happen only during night time
One process occurs during day time and other at night
One process occurs during day time and other at night
Which of the following criteria dows not pertain to facilitate transport?
Requirement of special membrane proteins
High selectivity
Transport saturation
Transport saturation
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