Several tissues come together to form an what

Organs

Explanation:

When a group of tissues work together to perform a particular role in the human body, they make up an organ.

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.

since there are no options posted i'll give you a few examples.

a dolphin's flipper, bird's wing, cat's leg.