The factors of heredity

Case, the child's blood group is not the same as the parent that raises many questions. Opened up this question a scientist from Australia by K. Landsteiner. Studying the behavior of red blood cells in different people, he brought three of AOW. Some of the erythrocytes are evenly distributed, others are glued together. Inherited genes with information about the presence or absence of the agglutinogens. So there was I (OO), II (AA or AO) and III (IV or IN), and the fourth (AB) is opened a little later. In all compounds, the first letter means information about the presence or absence of agglutinogen that the child receives from mother, one from the father.

For example:
- when I (OO) no antigens A and b, therefore, if moms and dads are the first group, the child will inherit her;
one parent from the first, another the second, the offspring may be born with a I or II;
- if the mother II, and III of the father or Vice versa, the children will take any of the four;
- I and III give only the first and third;
- if parents have a fourth, the child will be born with any, except the first, as in the hereditary set contains both agglutinogens. Thus, the blood group of a child may not coincide with the parent.

From all rules there are exceptions

Scientists have revealed the fact of the exclusion when both parents have IV (AB), and the child is born with I (OO). In the blood agglutinogens are, but for some reason does not appear, the phenomenon investigated so far. Found this fact quite rare, even rarer in Caucasians. "Bombay phenomenon," as he is called, is often seen in dark-skinned people, the Indians.

A blood transfusion may affect genetic pattern that does not allow to determine the exact group from a newborn baby. Agglutinogenic composition can be modified by many factors to determine it is difficult. Therefore, the blood group of parents and children cannot be called interconnected at 100% and, moreover, to establish paternity for her. Initially, research on the presence of heredity were not conducted, are not conducted now.

The most common ones are I and II, they own nearly 40% of the population. The rarest is considered to be IV, which are only 3-5% of people.

In addition to the band, the blood is divided into RH - positive and negative. That also has its rules and exceptions. People I group negative RH-factor is considered a universal donor. Often in the world is required for IV transfusion with a positive rhesus factor.