Physiology_Lab_ Practical 2_ 6.3

If a person has blood type A, the possible genotypes that the person may have are _______ and _______

AA and AO

The rarest blood type is blood type

AB-

If a person who is blood type O marries a person who is blood type A, what are the possible blood types their children could have?

AO or OO

Explain how hemolytic disease of the newborn is produced. How may the disease be prevented?

Hemolytic disease of the newborn occurs only if the mother is Rh negative, with both the father and the baby Rh positive. At delivery, the mother's blood may be exposed to the Rh antigen from the baby's RBCs and, over time, develop antibodies against it. If a second developing child is also Rh positive, antibodies from the mother may cross the placenta and destroy the fetal RBC. The development of maternal antibodies against the Rh factor may be prevented by administration of Rh antibodies (RHOgam)usually once during pregnancy and again shortly after delivery. The injected anti-Rh antibodies will seek out, agglutinate, and destroy any Rh-positive fetal red blood cells that may have entered the mother's blood supply before her immune system could produce antibodies against them

The universal blood donor is blood type

O

The most common Rh type is

O+

Name the antigens present and absent on the surface of a red blood cell if the person is: type A negative type O positive type AB negative

Present:A Absent: B,Rh Present:Rh Absent:A,B Present:A,B Absent:Rh

There person most in danger of having a child who develops erythroblastosis fetalis is a woman who has the blood type ___________ when her husband has the blood type ______________

Rh negative; Rh positive

Can blood types be used in paternity cases to prove or disprove possible fatherhood? Give examples to support your answer.

Since blood type is the phenotypic expression of genotype blood types cannot be used to prove fatherhood but can be used to disprove fatherhood. For example, if a type O woman claims that a type A man is the father of her type O baby, the blood types in this case can neither prove nor disprove her claim. This is because the man who is type A may have either the genotype AA or the genotype AO. If he has the AA genotype, he cannot have fathered a type O child, but if he has the AO genotype, there is a 50% chance that he could have fathered a type O child.

What are the dangers of giving a person a transfusion when the blood types don't match?

The danger of mixing blood types that don't match is that red blood cells may clump together, or agglutinate. This clumping will plug blood vessels and prevent the normal flow of blood to the tissues.

Suppose a person who has type A blood receives large amounts of whole blood from a person who has the universal donor blood type. Will that be safe? Explain.

The safety depends on the amount of donor plasma. The donor blood type O will have RBCs with no antigens so no agglutination will occur, but the donated plasma will contain antibodies against the A antigens on the RBCs of the recipient. If some donor plasma is given, some agglutination of the recipient RBCs with anti-A antibodies from the donated plasma will occur. This agglutination by whole blood is often overlooked in emergency situations since the prime reason for the transfusion is to supply the victim with RBCs. Donated blood is usually centrifuged and the packed cells separated from the plasma so that when needed in an emergency, only the packed cells are given in a transfusion.