Briefly list AND describe your body's 3 lines of defense against things like viruses.

then that particular organisms become extinct.

the solute can move "downhill," from regions of higher to lower concentration, relying on the specificity of the protein carrier to pass through the membrane. this process is called passive transport or facilitated diffusion, and does not require energy.

it's diluted or concentrated

in a diluted solution, you can add a lot more solute but in concentrated only a little more can be added