Plant physiology

Plant-water relation lesson plan


Introduction to plant water relation


SUBJECT Plant physiology
TOPIC Introduction to plant water relation
AVERAGE AGE 15-16 Years
DURATION 45 Minutes
TIME  8:45-9:30
DATE 17/2/2021
INSTRUCTIONAL MATERIALS Chart and video clip showed plant water relation.


PREVIOUS KNOWLEDGE The students have already been taught the meaning of plants and types of soil suitable for planting.






At the end of the lesson, the students would be able to know plant water relations.
INTRODUCTION The teacher explains how plants control the dehydration of their cells, including the collection of water from the soil, how water is transported within the plant, and how water is lost by evaporation from the leaves














The teacher explains the relationship between water and plant. The teacher explains to the students that water is the most abundant constituent of all physiologically active plant cells. The smallest water contents in living parts of plants occur mostly in dormant structures, such as mature seeds and spores. The great bulk of the water in any plant constitutes a unit system. This water is not in a static condition. involves absorption of water from the soil, its translocation throughout the plant, and its loss to the environment, principally in the process known as transpiration but also through flow across cells in the roots and leaves.

Plant water relation

Plant Water Relation as an Osmotic System

The plasma membrane of a leaving cell is a differentially permeable membrane and the cell sap contained in the vacuoles is an aqueous solution of salts and sugars with a high osmotic potential. Since cells of a plant are in contact with a watery medium or with other cells containing water, they may absorb or lose water by osmosis. When a cell is placed in a hypotonic solution, ( i.e. a solution whose osmotic potential is lower than that of the cell sap) water enters the cell. This inward movement of water into a cell is said to be endosmosis. On the contrary, when a cell is placed in a hypertonic solution, ( i.e. a solution whose osmotic potential is higher than that of the cell sap) water moves out of the cell. This outward movement of water from the cell is called exosmosis. In making of plant water relation in a plants life osmosis plays very important role It helps in absorption of water from te soil and maintains the turgidity of cells.It also assist in closing and opening of stomata.

Role of Diffusion in Plant Water Relation

Diffusion plays an important role in several vital processes in plant water relation. It helps in the exchange of gases during photosynthesis and respiration; and in transpiration water vapors diffuse from the intercellular spaces toll outer atmosphere. During the passive salt uptake ions are absorbed by the simple process of diffusion.


















The teacher summarizes the lesson by re-explaining the key points of the topic.






 The teacher evaluates the lesson by



















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