Name the immune protein present in the blood.

Mature human $RBCs$ are enucleated. Which of the following is the most appropriate explanation for this?
$(i)$ They do not need to reproduce.
$(ii)$ They are somatic cells.
$(iii)$ They do not perform metabolism.
$(iv)$ Their internal space is available for $O_2$ transport.

Vascular tissue or fluid tissue is made up of

The haemoglobin content per $100 \ ml$ of blood of a normal healthy human adult is

Name the blood component which is a viscous and straw-coloured fluid.

Which major types of blood groups are found in human beings?