Tag: diffusion

 For plants to take up mineral ions, ions are moved into root hairs, where they are in a higher concentration than in the dilute solutions in the soil. Active transport (pumps) then occurs across the root so that the plant takes in the ions it needs from the soil around it. The root hair cells have carrier molecules on their surface that pick up the minerals and move them into the cell against the concentration gradient.

(A) The upward flow of the water is seen in the roots of the plant.

Plants absorb their mineral salt supply from the soil through the roots from the zones of elongation and root hair. The minerals are absorbed as ions which are accumulated by the plants against their concentration in the soil.

Solar heat causes the evaporation of water from the surface of the leaves in form of water vapour through small openings called stomata. This loss is known as transpiration. Due to the loss of water, water stress condition is created that forces the upward movement of water from the soil towards the shoot system. This water is then again distributed to various plant parts.

Diffusion is a type of passive transport which do not require expenditure of cellular energy for the net movement of a substance from a region of high solute concentration to a region of low solute concentration. This is also referred to as the movement of a substance down a concentration gradient.

Diffusion is a passive movement of molecules along their concentration gradient. While osmosis is the diffusion of water molecules through a differentially permeable membrane or semipermeable membrane.

The same conditions of temperature and pressure, the molar mass is proportional to the mass density. Therefore, the rate of diffusion of different gases is inversely proportional to the square root of their mass densities.

Gas exchange is the process that occurs between oxygen and carbon dioxide. Oxygen is passed from the lungs to the bloodstream and carbon dioxide is eliminated from the bloodstream to the lungs. Exchange of Gas takes place in lungs between the alveoli and capillaries which are tiny blood vessels, placed at the walls of alveoli. The rate of diffusion depends on the thickness of the biological membrane which forms the boundary between the external environment and organisms.

Diffusion is a process in which the gaseous molecules spreads due to their kinetic energy and movement of molecules from their higher concentration to their lower concentration. Hence, The correct answer is option B.

Diffusion is the process of spreading of the gaseous molecule according to their kinetic energy. In this process, particles move from an area of high concentration to an area of low concentration. If the perfume is sprayed in one corner of a room, it will be smelt soon after in the opposite corner. Since the perfume molecules are in constant random motion they bump into each other causing some molecules to be occasionally sent hurtling out of the mass. Gradually, the molecules spread out.