Are plants completely
independent from other
organisms?

no

Explanation:

Nothing is ever completly indepenet from other organisms because everything relies on evreything else such as a plant relies on bees and other insects and animals to pollinate them they also rely on animals to die and fertalize the soil

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.