Every cell has different receptors in the membrane, these receptors are specific, but different receptors can read one signal molecule, according to the receptor, this molecule can activate or inactivate different path ways.
Let me put it this way, if I give the same message to a botanist and a gardener they both are going to read it in different way even knowing it is the same.
Tides are long waves that moves across the oceans and are caused by the gravitational forces exerted on the earth by the moon and the sun. The coastal areas experience high tides when gravity pulls ocean towards the moon, this phenomena happens twice a day.
