Which blood group is rhesus negative

Inheritance of blood types

Possible combinations of blood groups

Determine the possible blood types of your children by entering the blood types of the parents

 

mother

father

Possible blood groups of the children

 


The blood type

results from the
Antigenic characteristics

either pure or mixed

Only one antigenic characteristic is given to the at a time
next generation inherited.

The Mendelian inheritance rules

Everyone has a very specific blood group pattern. This pattern remains the same throughout life and is inherited according to fixed inheritance rules, the so-called Mendelian inheritance rules. These hereditary rules were named after the natural scientist Gregor Johann von Mendel, who systematically carried out cross-breeding experiments with peas and beans in 1865, the findings of which could later be transferred to all sexual reproductive processes. However, Mendel's laws were not recognized as generally applicable laws of inheritance until 1900, when other researchers (C. E. Correns, E. Tschermak and H. de Vries) independently discovered the meaning of the laws of inheritance.

Inheritance of AB0 blood groups

Mendel's laws precisely define how human blood groups are inherited. The AB0 blood group system divides people into blood groups according to the various antigenic characteristics of the red blood cells:
A means that the antigen A is present, which produces antibodies against the blood cell surface of group B. People of blood group B have the antigen B and thus antibodies against blood group A. With blood group 0 there are no antigens, but antibodies A and B are present, people of blood group AB have both antigens A and B, but no antibodies.

Blood group inheritance

Everyone has two antigenic characteristics, only one of which is passed on to the next generation. In the newborn, the blood group is thus made up of the inherited trait from the mother and the inherited trait from the father. Characteristics A and B are equally important to one another, but inherited dominantly compared to antigen 0. These inheritance relationships result in the following blood group combinations for the child, depending on the inherited antigenic characteristics of the parents.

Inheritance of the rhesus factor

The inheritance of the Rhesus factor also proceeds according to Mendel's genetic rules. In the rhesus system, a distinction is made between the presence (rhesus-positive) and the absence of the rhesus feature (rhesus-negative). If someone is rhesus-positive, it means that the rhesus antigen is present on the red blood cells; in rhesus-negative people, the antigen is absent. In heredity research, the genes that cause the formation of the rhesus antigen are referred to as D genes. In addition, there are the d genes in which no rhesus antigen can be formed. Everyone has the rhesus trait twice, with only one trait being inherited. As with the AB0 blood group system, the two genes D and d are inherited in a certain succession. The D gene dominates over the d gene (recessive), which is why it decides on the rhesus type. A rhesus-positive person can therefore have the gene combination Dd (mixed-breed) or DD (pure-blooded), while a rhesus-negative person can only have the pure-blooded gene combination dd. If both parents are rhesus negative (dd), the child is also rhesus negative in any case, since it can only inherit the d gene from both parents. A rhesus-positive child cannot come from a pair of parents who are rhesus-negative. An extended rhesus formula, such as B. CcD-ee, which includes further fine differentiations of the rhesus blood group (the antigens C, c and E, e). They can occur in any combination with the rhesus feature.

Possible blood groups of the children

The characteristic 0 is always suppressed by the A or B antigen, i.e. inherited recessively. This means that with a combination of the dominant A or B characteristic with the recessive 0 characteristic, blood groups A and B always dominate and decide on the blood group type. People of blood group A can therefore either have the antigen A (AA, i.e. pure hereditary) or the gene combination A0 (mixed hereditary), in which blood group 0 is inherited recessively and thus suppressed. The same applies to people with blood group B. They either have the gene combination BB or B0. People of blood group AB have both antigen A and antigen B, since antigens A and B are inherited equally among each other.

The blood group inheritance rules also play an important role in forensic medical reports or proof of paternity, as the possible blood groups of the parents can be determined via the blood group of the child. Have z. B. Both parents have blood group AB or are genetically A or B, they cannot have children with a mixed blood group (A0 or B0) or even blood group 0.



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