Answer:
A gene that stimulates and controls the production of white blood cells.
Step-by-step explanation:
First, it is necessary to know that a gene is a sequence of DNA that has information for the formation of molecules necessary for the body. These molecules can be proteins, cells, enzymes, among other things that are needed at that very moment.
When a person on superficial scratches, the skin cells send a signal that it is necessary to defend the injured part from possible invaders that could harm the organism. At that moment, the genes come into action and are quickly expressed, not all of the organism's genes, but only those that contain information for the production and control of defense cells, the white blood cells, which will prevent invaders from using the scratches as entry into the body and cause damage.