Rachel A platelet has a very significant, but some what odd job. When a blood vessel gets cut,the platelet sticks to the cut until the blood clots. Without platelets people would bleed to death, all because of a mere cut.
Clotting factors are a protein in the plasma.
They are found in an inactive part of the blood. If a blood cell is damaged it and the platelet send off chemicals that react with the clotting factors. The clotting factors criss-cross over the platelets making sure no blood gets through. The criss-crossing pushes out the fluid that is laying on the top. A clot on the skin is called a scab.