1. Water absorption in root hairs occurs through a process involving imbibition, followed by diffusion and osmosis. 2. As water enters the root hair cell, it undergoes an increase in turgor pressure, resulting in turgidity. 3. The root hair cell possesses lower solute concentration (D.ED.) compared to the adjacent cortical cell with higher solute concentration … Read more
A ‘necessary evil’ as termed by curtis transpiration because: 1. Stomata, small openings in the leaf epidermis, facilitate 90–93% of transpiration, a vital plant process. 2. To enable gaseous exchange through diffusion, stomata must remain open during this essential biological activity. 3. Gaseous exchange is crucial for both respiration and photosynthesis within plants. 4. The … Read more
Capillarity theory of water translocation: 1. Bohem proposed the capillarity theory of water translocation.Capillarity arises from the interplay of surface tension, cohesive forces, and adhesive forces among water molecules. 2. Xylem vessels and tracheids are tubular elements characterized by their luminal structure. 3. Within these elements, a water column is sustained through the synergistic influence … Read more
Significance of transpiration: 1. Facilitating a cooling effect by absorbing plant heat and converting water into vapor during transpiration. 2. Ensuring optimal turgor pressure by absorbing excess water during transpiration, promoting healthy growth. 3. Assisting mineral transport by generating a transpiration pull, aiding the roots in absorbing and distributing soil minerals. 4. Supporting water transport … Read more
Transpiration is the process wherein water is lost from the plant body in the form of vapor. Role of transpiration: 1. Eliminates excess water. 2. Facilitates passive absorption of water and minerals. 3. Aids in the ascent of sap through transpiration pull. 4. Sustains cell turgor. 5. Provides a cooling effect by reducing temperature. 6. … Read more
Transpiration is the process in which water is lost in the form of vapor. Mechanism of closing and opening of stomata is as follows: Stomatal transpiration primarily involves minute pores. Stomata consist of two guard cells encircled by accessory cells. The opening and closing of stomata are regulated by the turgidity of guard cells. When … Read more
Theories of water translocation: The translocation of water is explained by various theories: 1. Vital force theories 2. Root pressure theory 3. Capillary force theory 4. Cohesion force theory Root pressure theory: Root pressure, once believed to drive water up plant stems, faces objections. The force is weak (max 2 atm), insufficient for tall trees. … Read more
A mechanism of water absorption: Water is absorbed through two mechanisms: active absorption and passive absorption. Active absorption: 1. Osmotic Active Absorption: This process involves water absorption through osmosis, where water moves into the root xylem against the concentration gradient of the root cell. The high concentration of solutes in the cell sap and the … Read more
The symplast pathway across the root occurs when water, absorbed by root hair, moves through living cells via plasmodesmatal connections between them.
1. During the daytime, the enzymatic activity of phosphorylase facilitates the conversion of starch into sugar, contributing to increased sugar levels. 2. Conversely, during the nighttime, there is a reversal in this process, with sugar being converted back into starch through the action of phosphorylase. 3. These diurnal variations in enzymatic activity result in dynamic … Read more