What is the maximum period within which stored blood should be transfused?

$Serum = .........$

What does a decrease in the number of blood platelets lead to?

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.

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

The process of formation of blood corpuscles is called