Cells produced in the bone marrow include .......

Mammalian $RBCs$ are..... in shape.

Which one of the following blood cells produce antibodies as an immune response of the body?

What is thrombin?

Select the correct statement/s regarding blood groups in human.
$i$. Some genetically determined blood group systems are $ABO$, $Rh$, $Duffy$, $Lewis$, $Bombay$ blood group etc.
$ii$. Three types of agglutinogens are present on surface of human $RBCs$ such as $A$, $B$ and $D$.
$iii$. Individuals with blood group "$AB$ $Rh$ $+ve$" have $A$, $B$ and $D$ antigens on the surface of their $RBCs$ and both antibodies 'a' and 'b' in their plasma.
$iv$. Haemolytic disease of Newborn occurs when mother with $Rh$ $-ve$ blood group conceives $Rh$ $-ve$ foetus.
$v$. Individuals with '$AB$' blood group are called universal donors while those with '$O$' blood group are called universal acceptors, with reference to blood transfusion.

In which state is iron present in hemoglobin?