Prothrombin is

Which of the following statements is $NOT$ true for $WBC$s?

Give the differences between $RBCs$ and $WBCs$.

What happens when calcium is removed from freshly collected blood?

$A$ person with an unknown blood group under the $ABO$ system has suffered significant blood loss in an accident and requires an immediate blood transfusion. $A$ friend,who has a valid certificate of their own blood type,offers to donate blood without delay. What would be the blood group of the donor friend?

Which of the following cells act as phagocytes?
$I$ - Neutrophils,$II$ - Monocytes
$III$ - Lymphocytes,$IV$ - Eosinophils,$V$ - Basophils