Mammals have biconcave $RBCs$. The physiological advantage of this shape is:

Which disease can be caused by the $Rh$ factor?

The ion present in the highest concentration in blood plasma is........

Plasma is a straw-coloured,viscous fluid constituting nearly $A$ $\%$ of the blood,$B$ $\%$ of the plasma is water,and proteins constitute $C$ $\%$ of it. Choose the correct option for the blanks $A, B$,and $C$.

$A$ person injured in a road accident does not have a known blood group and requires an immediate blood transfusion. $A$ doctor friend offers to donate blood immediately. What would be the blood group of this doctor?

In the $ABO$ blood grouping system,if both antigens are present but no antibodies are present,the blood group of the individual will be ...................