Answer:
The correct answer is A cell surface receptor molecule becomes activated by binding to a molecular signal.The cell does not return to its normal activities after signal has exerted its effect.
Step-by-step explanation:
Cell signalling deals with the binding of sinalling molecule to the receptor present in the surface or interior of the target cell,the binding of signalling molecule activates the receptor,the activated receptor then carry the signal to the interior of the cell, the transmitted signal to cell"s interior activates many protein such as enzymes that carry out the further cellular and physiological processes related to the activity of that cell.
But after all of these incidents the cell returns to its normal state to carry out another cycle of signalling process.