Which of the following are erythropoietic organs?
$I$. Liver
$II$. Lymph node
$III$. Spleen
$IV$. White bone marrow
$V$. Red bone marrow
Choose the correct option.

Write the feature that distinguishes between the two: Plasma and Serum.

What is the percentage of neutrophils found in a $DLC$ (Differential Leukocyte Count)?

You are required to draw blood from a patient and to keep it in a test tube for the analysis of blood corpuscles and plasma. You are provided with the following four types of test tubes. Which of them will you $NOT$ use for this purpose?

For a child having blood group $B$,if the father has blood group $A$,what may be the blood group of the mother?

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