Question

Which of the following will not coagulate ?
A. Blood serum
B. Blood plasma
C. Lymph
D. Whole blood

Answer 1

Hint: Blood is a special connective tissue consisting of fluid matrix, plasma and formed elements. White blood cells, Red blood cells and Platelets are collectively called formed elements. When there is bleeding, special factors act in that area and cause clotting of blood and therefore stops the bleeding. This process is termed as coagulation.

Complete Answer:
- Platelets are also called thrombocytes which are cell fragments produced from megakaryocytes which are special cells in the bone marrow. Platelets release a variety of substances most of which are involved in the coagulation of clotting of blood. Reduction in the number of Platelets can lead to clotting disorder which will lead to excessive blood loss from the body.
- Plasma is a straw coloured, viscous fluid containing nearly 50% of the blood. Factors for coagulation or clotting of blood are present in the plasma. So it can coagulate. Plasma also contains protein 6 to 8 per cent. Fibrinogen, globulins and albumins are the major proteins. Fibrinogens are needed for clotting of coagulation of blood.
- Blood plasma without the clotting factors is called blood serum. Since the clotting factors are absent in blood serum it cannot coagulate.
- Lymph is a tissue fluid. It is used in the exchange of nutrients between the blood and the cells.
- In blood, platelets are present due to which coagulation occurs in blood.

So the correct answer is (A).

Note: Blood exhibits coagulation or clotting In response to injury or trauma which is the mechanism to prevent excessive loss of blood from the body. There are a series of complex enzyme-linked reactions for the process of coagulation known as cascade process. Calcium ions play an important role in clotting.