IGCSE Biology

Explain the importance of active transport as a process for movement of molecules or ions across membranes, including ion uptake by root hairs

Describe active transport as the movement of particles through a cell membrane from a region of lower concentration to a region of higher concentration (i.e. against a concentration gradient), using energy from respiration

Explain the importance of water potential and osmosis in the uptake and loss of water by organisms

Explain the effects on plant cells of immersing them in solutions of different concentrations by using the terms: turgid, turgor pressure, plasmolysis, flaccid

Describe osmosis as the net movement of water molecules from a region of higher water potential (dilute solution) to a region of lower water potential (concentrated solution), through a partially permeable membrane

State that plants are supported by the pressure of water inside the cells pressing outwards on the cell wall

Investigate and describe the effects on plant tissues of immersing them in solutions of different concentrations

State that water moves into and out of cells by osmosis through the cell membrane

State that water diffuses through partially permeable membranes by osmosis

Describe the importance of diffusion of gases and solutes in living organisms