Selective permeability — Science definition
The property of letting some substances cross the membrane while blocking or controlling others; also called semipermeability.
Where it is taught
- The Cell Membrane — Cells, Membranes & Exchange, Life Science: Biology, Grade 10
In use
Add all this up and you get the membrane's defining property: selective permeability.
The Cell Membrane
Questions using selective permeability
Problem 1
Explain what 'selective permeability' means and why it is essential for a cell.
Answer and explanation
Selective permeability means the membrane lets some substances cross while blocking or controlling others. It is essential because it lets the cell keep its internal chemistry different from the outside — taking in what it needs, removing wastes, and keeping harmful things out — which is the basis of homeostasis.