What is the principal cation in human blood?

The largest corpuscles in mammalian blood are

Match the terms in Column-$I$ with their explanation in Column-$II$:

Column-$I$	Column-$II$
$A$. Polycythemia	$I$. Decrease in number of WBCs
$B$. Erythrocytopenia	$II$. Increase in number of RBCs
$C$. Leukemia	$III$. Decrease in number of RBCs
$D$. Leucopenia	$IV$. Uncontrolled increase in number of WBCs

What is the medium of transport in higher organisms?

If the mother has blood group $A$ and the father has blood group $AB$,which of the following blood groups cannot be present in their child?

Which of the following statements are correct?

$A$. Basophils are most abundant cells of the total WBCs

$B$. Basophils secrete histamine, serotonin and heparin

$C$. Basophils are involved in inflammatory response

$D$. Basophils have kidney shaped nudeus

$E$. Basophils are agranulocytes

Choose the correct answer from the options given below: