Option 1 is incorrect as blood platelets do not have prominent nuclei. They are actually small cell fragments that are formed from megakaryocytes in the bone marrow.
Option 2 is incorrect as blood platelets are not involved in phagocytosis. Their main function is in blood clotting to prevent excessive bleeding.
Option 3 is incorrect as blood platelets do not contain haemoglobin. Haemoglobin is found in red blood cells and is responsible for carrying oxygen.
Option 4 is correct. Blood platelets are also known as thrombocytes. They play a crucial role in blood clotting by forming a plug at the site of injury and releasing chemical signals to help promote clotting.