Which of the following prevent$(s)$ blood clotting in uninjured blood vessels?

Statement-$I$ : Two surface antigens may be present on the $\text{RBCs}$.
Statement-$II$ : Antigens are chemicals that can induce immune response.

Write the feature that distinguishes between the two: Plasma and Serum.

Which white blood cell has a kidney-shaped nucleus?

What is the proportion of $Rh$ $^{\text{+ve}}$ individuals in the human population?

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