Final answer:
Platelets are cell fragments formed from megakaryocytes in the bone marrow, playing a crucial role in blood clotting by adhering to injury sites and forming fibrin clots.
Step-by-step explanation:
Platelets, also known as thrombocytes, are cell fragments that are crucial for blood clotting processes. They are produced from large bone marrow cells called megakaryocytes.
These megakaryocytes release thousands of cytoplasmic fragments, each enclosed by a bit of plasma membrane, into the bloodstream to become platelets. Platelets play a fundamental role in hemostasis, adhering to the site of blood vessel injuries, forming plugs, and releasing chemicals necessary for the formation of a fibrin clot. This process is critical for preventing blood loss and facilitating wound healing.