Average life span of human $RBC$ is

Which of the following is true about plasma?
$(i)$ It contains $90-92 \%$ water.
$(ii)$ It contains $6-8 \%$ proteins.
$(iii)$ It is a straw-coloured,viscous fluid.

The blood glucose level is commonly expressed as:

Universal donors have no antigens on $RBC$s and have both $a$ and $b$ antibodies. They belong to blood group:

Identify the function of the cell shown in the image.

Biological marriage of one of the following should be avoided: