1. Introduced by Dixon and Jolly in 1894, this theory currently stands as the widely accepted explanation for the upward movement of sap in plants. 2. Grounded in two fundamental principles—cohesion and adhesion, along with transpiration pull—this theory delineates the mechanism behind sap ascent. 3. Cohesion and adhesion dynamics involve the cohesive force among water … Read more
1. Root hairs, originating as tubular extensions of epiblema cells, play a crucial role in absorbing capillary water from the soil. 2. The absorption of water involves three key physical processes: imbibition, diffusion, and osmosis. 3. Imbibition occurs as water molecules are adsorbed on the cell wall of the root hair, contributing to the overall … Read more
1. The absorption of water by plants is facilitated through the intricate network of root hairs embedded in the soil. 2. Root hairs, strategically located in the zone of absorption, play a vital role in the uptake of water and essential nutrients. 3. Originating as unicellular extensions, these root hairs are ephemeral structures formed by … Read more
i. The examination of plant ash reveals the absorption of minerals by plants from the soil and their surroundings. ii. Plants absorb minerals primarily in the ionic (dissolved) form through their roots, and subsequently, these minerals are transported within the plant. iii. The absorption of mineral ions operates independently of water absorption. iv. Mineral ion … Read more
1. Macronutrients, such as carbon (C), hydrogen (H), oxygen (O), nitrogen (N), sulfur (S), magnesium (Mg), calcium (Ca), potassium (K), etc., are essential minerals needed in significant quantities for plant metabolism. 2. Micronutrients, including copper (Cu), cobalt (Co), manganese (Mn), boron (B), zinc (Zn), chlorine (Cl), etc., are minerals needed in small quantities for essential … Read more
A) Osmotic pressure is the minimum pressure needed to prevent the inward flow of a pure solvent through a semipermeable membrane. Turgor pressure, inside the cell, pushes the plasma membrane against the plant cell wall. Turgor Pressure vs. Osmotic Pressure: Turgor Pressure 1. Turgor pressure arises in the cell due to osmotic water entry, maintaining … Read more
(i) Osmosis is a specific type of solvent diffusion through a semipermeable membrane. (ii) It involves the movement of ions, atoms, or molecules from areas of higher concentration to regions of lower concentration. (iii) When a living cell undergoes exo-osmosis in a hypertonic solution, it experiences plasmolysis. (iv) The swelling of hydrophilic colloids due to … Read more
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