Which one of the following is correct?
- Lymph = Plasma + RBC + WBC
- Blood = plasma + RBC + WBC + Platelets
- Plasma = Blood - Lymphocytes
- Serum = Blood + Fibrinogen
Answer
(2) Blood = plasma + RBC + WBC + Platelets
Solution
As per NCERT, blood consists of a fluid matrix, plasma, and formed elements — erythrocytes (RBC), leucocytes (WBC) and platelets.
(1) Lymph has no RBCs. ⇒ incorrect
(3) Plasma = Blood - all formed elements (not only lymphocytes). ⇒ incorrect
(4) Serum = Plasma - clotting factors (fibrinogen etc.). ⇒ incorrect
∴ Blood = plasma + RBC + WBC + Platelets is correct.
Answer: (2)