A group of cells that performs a similar function is known as tissue.
The prevalence rate of a disease refers to the number of people in a population that are affected by a particular disease. The only two reasons why the number of this set of people will decrease is if a cure is found for the disease or if those affected are dying.
Cure or death will reduce the prevalence rate.<span />
The data you will collect is the blood phenotype.By adding serums that each contains a particular antibody such as anti-A, anti-B, or anti-D ... to see if there's an agglutination with erythrocytes' antigen and the antibodies, proving the presence of the appropriate antigen in the blood.
This will help to confirm the blood grouping if this technique is done in parallel with the plasma test ( of Simonin-Michon).