# How To Determine The Blood Group By The Father

## Video: How To Determine The Blood Group By The Father

Blood type is an important inherited trait. It does not change throughout life and depends on the presence or absence of antigens A and B in erythrocytes. Knowing your blood type can come in handy in an emergency, but you don't always need to get tested to determine it. In some cases, the blood group can be calculated by knowing the mother and father groups.

## Instructions

### Step 1

The traditional principle of dividing blood into groups is the AB0 system. It was named so for a reason. If there are no A and B antigens in a person's erythrocytes, then blood of the first group (00) flows in his veins. The presence of antigen A indicates that human blood belongs to the second group (AA or A0). Antigen B is a trait of the third group (BB or B0). And the presence of both antigens makes a person the owner of a rare, fourth blood group (AB).

### Step 2

Knowing the blood groups of the parents, one can assume (and in some cases determine with 100% certainty) the child's blood group. If the father and mother have the first group (00), the child will definitely inherit it. There can be no other options in this case, since antigens A and B, which are absent in the erythrocytes of the parents, are simply nowhere to be found in the child's blood. However, a mother with a zero group will not always have the same child. If the father has a group A0 or B0, the baby can inherit it. The same characteristics (A0 or B0) will be possessed by the blood of a child born to a father with the fourth group.

### Step 3

If the mother has the second blood group, and the father has the first, the child can only inherit them. In addition, according to the laws of genetics, they can also turn out in a baby, even if both parents have group A0. Even more interesting combinations are possible in a child from mother A0 and father B0: in this case, the blood type can be absolutely any. But children from parents with the second and fourth groups can inherit any, except the first.

### Step 4

What if the mother has a third group? And in this case, the child's blood type can be any, depending on the father's group. If he is the owner of zero or third, the baby can also have 00, B0 or ​​BB. If the father has a second, the child has any options. And if the fourth - the baby will be born with any group except zero.

### Step 5

If the mother has a rare AB group, and the father has zero, the children will not inherit either one or the other. In such a situation, only the second and third groups are possible. If the dad has 2, 3 or 4 groups, the baby can be born with one of them.

### Step 6

Knowing the blood types of the mother and father, one can only assume the blood type of the child. It is possible to determine it accurately only with the help of laboratory analysis.