Answer:
The mark left after injured tissue has healed is called a scar.
Explanation:
Scar is a mark which is left on the skin where a wound, burn, or sore has not healed completely r just after it is healed. The human body produces a tough fiber in the body which gives the skin strength and flexibility. The fiber is known as collagen and it helps the body to reconnect the tissues broken apart by the injury. Since the question has been asked to tell the first letter of the word so the first letter of the word SCAR is "S".