A plant and animal cell both have a plasma membrane, ONLY a plant cell has a cell wall. Both of them have cytoplasm, a nucleus to guide them on what to do and ribosomes to produce protein. Only a plant contains a large vacuoles to store water and have chloroplast to do photosynthesis.
When cells communicate by the signaling process, one cell produces a signaling molecule that must be received by the signal receptor on or in the responding cell. Signaling molecules are often called ligands, a general term for molecules that bind specifically to other molecules (such as receptors).
