From the composition of antigens on the surface of red blood cells (red blood cells), a blood group is formed
Blood groups are four in total.
Human blood is characterized by the Rh factor. It indicates the presence or absence of the Rhesus protein and is designated Rh + or Rh-.
Today we will tell you in more detail how blood type is inherited.
The discovery of blood groups was made by Karl Landsteiner in 1900. Thanks to this, after 30 years he received the Nobel Prize.
In the second half of the 20th century, Austrian biologist and botanist Gregor Johann Mendel discovered the laws of heredity of blood groups.
We remind you who they are:
Group I (0) - erythrocytes do not contain agglutininogens, both types of agglutinins are present in plasma;
Group II (A) - agglutinin A is labeled on erythrocytes, agglutinin beta is in plasma;
Group III (B) - red blood cells contain agglutinin B, plasma - agglutinin alpha;
Group IV (AB) - there is an agglutinin on the erythrocytes, not a single agglutinin in the plasma.
Here are the rules by which a blood group is passed on to a child from parents:
- A child cannot have blood type IV if at least one of the parents is type I (0).
- The child can have any blood type except I (0) if the parents are fourth IV.
- If both parents have zero blood type, then the child will definitely inherit it.
- In parents with III and IV groups, children can be of any type of blood group.
- For parents with the same blood group (II or III), the child is most likely to be I (0).
Regarding the Rh factor, if both parents are Rh negative, then all children in their family will be Rh negative.
If one parent has a positive Rh factor and the other negative, then the child can be either positive or negative.
But if both parents are Rh positive, then in 75% of cases the baby will be Rh positive. However, the appearance of a child with a negative Rh factor in such a family is not an exception.