Answer:
In order to find the blood type of the shipmate, Gilligan mixes a little blood of the shipmate with himself firstly and than with individual blood types to simplify the data by process of elimination.
Step-by-step explanation:
There are a total of four types of blood groups which are as follows:
- A blood grp has anti B antibodies, has A antigen
- B blood group has anti A antibodies, has B antigen
- AB blood group has no antibodies, has A and B antigen
- O blood group has no antigens, has anti A and anti B antibodies
In order to find the blood type of the shipmate in the deserted needs of a blood transfusion, mixing of your blood with some of his blood is carred out:
- if no clumping seen then the shipmate has same type of blood group as you or has AB blood group (AB has no antibodies).
- If clumping is seen then person has O blood group(has both anti A and anti B antibodies) or the other type of blood group (that is if Gilligan's blood group is type B, if clumping is seen then the other person's blood group is O or A type because he has anti B antibodies in both of them)