In $.....$,blood cells are produced by the bone marrow.

Why do we consider blood as a connective tissue?

The red colouring matter of blood which transports oxygen contains an element in a system of rings. The element is:

In which part of the blood are immunoglobulins found?

$A$ person with blood group $A$ requires blood. The blood group which can be given is

Match the type of blood cells in Column $I$ with their respective structure in Column $II$ and function in Column $III$ and select the correct option given below.

Column $I$	Column $II$ $\&$ $III$
$I$. Erythrocytes	$D$. Enucleated,biconcave circular in shape; $N$. Transport of gases $O_2$ and $CO_2$.
$II$. Neutrophils	$A$. Spherical large cells,nucleus with many lobes; $O$. Phagocytic in function.
$III$. Lymphocytes	$C$. Spherical nucleus,agranular cytoplasm; $M$. Humoral and cell-mediated immunity.
$IV$. Thrombocytes	$B$. Cellular fragments small,oval shaped; $L$. Clotting of blood.