How many blood types do humans have?

Everyone has a blood type, and the specific blood type is mainly determined by our genes. When a child is born, half of the genes come from the father and half from the mother. When the mother and father combine, the child's unique genetic indicators are formed. When a human body loses too much blood and needs a blood transfusion, it is usually necessary to distinguish them based on blood type. Only people with the same blood type have the possibility of a successful blood transfusion. So how many blood types do humans have?

The human blood type system is a classification based on the differences in human red blood cell surface antigens. Due to the different agglutinogens contained in human red blood cells, blood is divided into several types, hence the name blood type. When the red blood cells of a person with different blood types are mixed with the serum of another person, the red blood cells stick together and undergo agglutination reaction, causing damage to the red blood cells and hemolysis. There are many types of human blood types, and each blood type system is determined by genetic factors and has immunological characteristics. The most common blood type system is the ABO blood type, which is divided into four types: A, B, AB, and O; the second is the Rh blood type system, which is mainly divided into Rh positive and Rh negative; and the third is the MN and MNSs blood type systems. According to current clinical tests at home and abroad, there are more than 30 types of human blood types.

Human blood type is hereditary. When the blood type genes of both parents combine in the sex cells of both sexes, they can pair up in the chromosomes of the cell nucleus, thereby passing the blood type genetic characteristics to offspring.

Different blood types have different genetic genes:

1. The genetic gene of type A blood can be the combination of A and A of both sexes to form AA, or it can be the combination of the A gene of one sex and the O of the other sex to form AO. But no matter whether it is AA or AO, the blood type that is displayed is type A, and O is a recessive genetic gene and cannot be expressed.

2. The genetic genes of type B blood are similar to those of type A blood. Some are BB, some are BO, but all that appear are B.

3. The genetic genes of AB type and O type blood are consistent with the blood type they express, AB type is AB and O type is OO. From this we can see that if the father and mother are type A or type B blood, their children may be type A or type B, but they may also be type O, because type A or type B both contain the recessive genetic gene O. When the O in the father's genetic gene combines with the O in the mother's genetic gene to form OO, it manifests as type O.

The various genetic genes of the parents' blood types will be recombined when the two sexes combine, and then reorganized to form the various blood types of their children. There is a certain blood relationship between children and their parents' blood types, but they are not necessarily the same.