The cell membrane allows which tiny molecules to move freely through it.
Starch is a ... and is ... to pass through.
The cell membrane is said to be...
Diffusion is a ..., it ... require energy.
What is the definition of diffusion?
In diffusion, molecules always move along a concentration gradient from ... to ... concentration.
Diffusion is the means by which useful substances such as ..., enter a cell and waste materials such as ..., leave a cell.