Final answer:
A mass of platelets that reduces minor bleeding following an injury is known as a platelet plug, which leads to the formation of a fibrin clot that seals the wound.
Step-by-step explanation:
The term for a mass of platelets that reduces minor bleeding following an injury is a platelet plug. Platelets, also known as thrombocytes, flock to the site of an injury and adhere to the wound area. They extend projections and release substances that activate other platelets and the coagulation factors in the blood. These factors cause the conversion of fibrinogen to fibrin, resulting in a fibrin clot, which is non-water soluble and effectively stops the bleeding. This accumulation and adhesion of platelets at the site form the platelet plug, which seals the wound temporarily while the body undertakes more durable repairs.