The lifespan of human white blood cells (leukocytes) is approximately ......... .

$A$ man whose blood group is not known meets with a serious accident and needs blood transfusion immediately. Which one of the blood groups readily available in the hospital will be safe for transfusion?

If a human mother has '$O$' blood group,the foetus would die if the blood of the foetus is

If $RBCs$ are placed in distilled water,the corpuscles will

Assertion: The regulation of $RBC$ production is accomplished by $FSH$.
Reason: Erythropoietin hormone circulates to red bone marrow where it increases stem cell mitosis and speeds up the development of $RBCs$.

Which of the following is incorrect regarding blood plasma?