Q.Differentiate between the following:

1. Diffusion vs Osmosis: Diffusion is the movement of any substance (solid, liquid, or gas particles) from a region of higher to lower concentration, and does not require a membrane. Osmosis is specifically the diffusion of water (solvent) molecules across a selectively permeable membrane, from a region of higher water potential to lower water potential — osmosis is a special case of diffusion.
2. Transpiration vs Evaporation: Transpiration is the loss of water in vapour form specifically from the living aerial parts of a plant (mainly through stomata), a biologically regulated process. Evaporation is the plain physical conversion of liquid water to vapour from any wet surface, living or non-living, and is not under biological control.
3. Osmotic pressure vs Osmotic potential: Osmotic pressure is the pressure that must be applied to a solution to just prevent the net entry of water into it by osmosis from pure water — it is a positive value. Osmotic (solute) potential is the corresponding component of water potential due to solutes and is always negative — numerically equal to osmotic pressure but opposite in sign.
4. Imbibition vs Diffusion: Imbibition is a special type of diffusion in which water is absorbed by a solid adsorbent (like a dry seed or wood), which then swells; it requires an imbibant with a very low (negative) water potential. Diffusion is the general movement of particles down a concentration gradient and does not require an adsorbent. …

1. Diffusion and Osmosis Diffusion is the net movement of particles — of a solid, liquid, or gas — from a region of their higher concentration to a region of their lower concentration, driven by random molecular motion; it does not require any membrane and can involve any kind of particle. Osmosis, by contrast, is a special, restricted case of diffusion: it refers specifically to the movement of water (solvent) molecules across a selectively/semi-permeable membrane, from a region of higher water potential (e.g., pure water or a dilute solution) to a region of lower water potential (a more concentrated solution). Every osmotic movement is a diffusion of water, but not every diffusion is osmosis.
2. Transpiration and Evaporation Transpiration is the loss of water in the form of vapour specifically from the living aerial parts of a plant — chiefly through the stomata, and to a lesser extent through the cuticle and lenticels. Because it happens through a living, regulated structure (the stomatal guard cells), transpiration is under physiological/biological control. Evaporation, on the other hand, is a purely physical process: the conversion of liquid water into vapour from any wet surface — living or non-living — and it proceeds according to simple physical laws (temperature, humidity, air movement) without any biological regulation.
3. Osmotic Pressure and Osmotic Potential Osmotic pressure is defined as the pressure that must be applied to a solution to just prevent the net inward movement (by osmosis) of pure water into it across a semipermeable membrane; it is expressed as a positive quantity, and is a colligative property — depending only on the number of solute particles, not their identity. Osmotic potential (also called solute potential, ψs) is the component of water potential contributed by dissolved solutes; it is always negative (zero only for pure water). Osmotic potential and osmotic pressure are numerically equal in magnitude for a given solution but are opposite in sign.
4. Imbibition and Diffusion Imbibition is a special type of diffusion in which water (or another liquid) is absorbed by the matrix of a solid, typically a colloidal or hydrophilic adsorbent such as a dry seed, dry wood, or gelatin, causing it to swell and generating imbibition pressure. It requires the adsorbing material (the imbibant) to have a very low (highly negative) water potential relative to the liquid imbibed. Diffusion in general is simply the movement of any particles from higher to lower concentration and does not require a solid adsorbent to occur.
5. Apoplast and Symplast pathways The apoplast pathway is the movement of water (and dissolved minerals) through the continuum of cell walls and intercellular spaces — a non-living pathway — driven by capillary and adhesive/cohesive forces, and it does not cross any membrane until it reaches the endodermis, where the Casparian strip blocks further apoplastic movement, forcing water into the symplast. The symplast pathway is movement through the interconnected cytoplasm of living cells, linked via plasmodesmata; to enter the symplast, water must cross at least one membrane (the plasma membrane), and once inside, it can move from cell to cell without crossing further membranes because the cytoplasm forms a continuous system.
6. Guttation and Transpiration …

Take each pair one at a time and identify the single defining axis of difference (state of water moved, membrane involvement, sign of the value, or timing/driving force), then state both terms symm …

• Defining only one member of each pair and leaving the other vague, instead of drawing an explicit contrast.
• Mixing up the sign convention for osmotic pressure (positive) and osmotic/solute potential (negative). …