Within an organism it is critical that signals between cells are very specific.

for example, if ligand a is meant to activate immune system cells to reproduce in response to an infection, it should not also cause other cells to grow as if they had received a growth hormone.

when a ligand is released, what prevents all of the cells in the body from being affected?

When a ligand is released what prevents other cells from being affected is ;

It is vital that in an organism the signal found between the cells of the organism must be specific. Therefore in an organism the shape of a ligand and its receptor determines the specificity of the ligand.

For example the receptor of a ligand x found on a muscle cell ( like in cardiac muscle ) we not allow the binding of the ligands found on a different cells even if they are exposed to ligand x , due to the specificity of the ligand and it corresponding receptor.

Hence we can conclude that when a ligand is released what prevents other cells from being affected is that the ligand will have only one receptor which it binds to.

Learn more : link

Chemical signals are the secreted by signalling cells, usually volatile molecules known as ligands. Ligands bind to other molecule at specific sites. When ligands is released what prevent other cells from being affected is:

Organisms are the multicellular organisms, which communicates through the transmission of signals. The communication between cells occurs through the signalling molecules. These molecules are referred to as ligands.

For instance, the receptor of ligand A is present on the muscle cell will not allow the binding of different ligands found on different cells. If the cells are exposed to ligand A, the high specificity of the cells will allow binding of only corresponding receptor.

Therefore, when ligand is released it will bind to its corresponding receptor and would not affect the other cells.

To know more about ligands, refer to the following link:

link

the answer to your question is a plant