What are the misunderstandings about blood type

　Humans have only four blood types.
　　Many people believe that humans have only four blood types: A, B, O, and AB (abbreviated as ABO blood type). In fact, human blood types are very complicated. Except for identical twins, almost no two people in the world have exactly the same blood type. After calculations by experts, the conclusion reached is that the blood types of only 8 people out of a million people are similar. What we generally call ABO blood type is just the most common and important type in the human red blood cell blood type system. It has the outstanding advantages of simplicity and practicality, and is also the most widely used.
　　
　　The blood type is only used for blood transfusion.
　　Some people only know the ABO blood type and think that the blood type is only required for blood transfusion. In fact, human blood types are widely used. In addition to blood transfusions, they can also be used to confirm blood relationship, solve cases, diagnose genetic diseases, and perform organ transplants. For example, blood cell type (HLA) is determined by genetics, so it can be used to identify the relationship between father and son.
　　
　　The blood type is constant.
　　Most people think that the blood type of a person does not change throughout their lives. It is true that under normal circumstances, a person's blood type is produced when the fertilized egg is formed and remains unchanged until the end of life. However, in recent years, medical research has found that under some special circumstances, a person's blood type may also temporarily mutate. Such as patients suffering from leukemia, certain intestinal malignancies, aplastic anemia and other diseases, or during radiotherapy, the blood type may change temporarily, but when the symptoms are relieved or the radiotherapy is stopped, the original blood type can be restored.
　　
　　Judgment of blood type intelligence and personality are
　　current, and many people believe in some irresponsible and disrespectful propaganda in some newspapers and periodicals, and talk about a certain blood type being smart, a certain blood type active, and a certain blood type longevity. According to this statement, there are only a few simple types of people in the world, so these statements have no scientific basis. Although the human blood type depends on the parents, it is not determined by the parent or the mother but by both parties. Therefore, the blood type of most children may be different from the blood type of their parents. Only when the blood types of both husband and wife are O type, the blood type of their children can be confirmed to be the same as that of their parents, and they are also O type. However, personality and intelligence are not determined by genetic factors.