Final answer:
EDTA works by binding calcium ions needed for blood clotting.
Step-by-step explanation:
The anticoagulant EDTA works by binding calcium ions needed for blood clotting. Calcium ions play a vital role in the coagulation process, and EDTA removes these ions by forming insoluble salts, preventing blood coagulation. The removal of calcium ions helps to prevent the enzymic conversion of prothrombin into thrombin and the production of thromboplastin, which are essential for blood clotting.