Answer:
When clotting factors in the plasma are activated to form a blood clot, the fluid portion of plasma that remains is known as serum.
Step-by-step explanation:
The liquid part of blood is known as the plasma. it makes about 90 per cent of the blood and comprises of antibodies and the clotting factors.
If the clotting factors or the fibrinogens are removed from the plasma, then the fluid that remains is termed as serum. The blood serum contains useful proteins like the albumin and antibodies. The serum is the part of the blood that is mostly used for the diagnostic tests.