What is the meaning of diapedesis?

Biological marriage of one of the following should be avoided:

Megakaryocyte cells are .....

Which test tube from the given options is $NOT$ used for keeping blood in a non-coagulated state for the analysis of blood corpuscles?

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:

What is the ratio of $WBC$ to $RBC$ in human blood?