Question

We add fertilisers and manures into the soil for better growth of the plant. How do these minerals enter into the plants? Identify the process involved

Answer 1

The concentration of minerals in the soil is very low. They dissolve in water and move around the soil in solution. Root hair cells are adapted to absorb the water out of soil by osmosis – they have a large surface area, thin walls and are close to the xylem cells used for transporting water up the plant. Mineralssuch as nitrate ions cannot be absorbed by osmosis (which is the movement of water only) or diffusion (because the minerals are in very low concentration). 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. This requires energy, and is called active transport.