Blood Types Blood Types 3. Write down 3 questions & 3 facts 3. Write down 3 questions & 3 facts you know about blood.you know about blood.

Read pgs. 324 beginning with Read pgs. 324 beginning with Multiple Alleles Govern Blood Multiple Alleles Govern Blood TypesTypes and finish at the end of 325 and finish at the end of 325

If possible answer any of your 3 If possible answer any of your 3 questions or add to your 3 facts if questions or add to your 3 facts if possible.possible.

Blood Typing Blood Typing

All ABO blood types are determined All ABO blood types are determined by 2 by 2 proteinsproteins called antigens, the called antigens, the AA antigen and the antigen and the BB antigen. antigen.

These proteins occur on the These proteins occur on the surface surface of red blood cellsof red blood cells. .

An individual’s blood An individual’s blood maymay contain contain one, both or neither of these antigens, one, both or neither of these antigens, forming the 4 blood groups: A, B, AB forming the 4 blood groups: A, B, AB and O.and O.

Blood Type A have the A antigen on Blood Type A have the A antigen on the red blood cells.the red blood cells.

Blood group B have the B antigen.Blood group B have the B antigen. Blood group AB have both A and B Blood group AB have both A and B

antigens. antigens. Blood group O have no antigens. Blood group O have no antigens.

The A and B alleles are dominant to The A and B alleles are dominant to the O allele. the O allele.

The A and B alleles are co-dominant The A and B alleles are co-dominant with one another. with one another.

Blood GroupBlood Group GenotypeGenotype

AA AA or AOAA or AO

BB BB or BOBB or BO

ABAB ABAB

OO OO OO

Antibodies are special immune cells Antibodies are special immune cells that destroy antigens that your body that destroy antigens that your body does not recognize. does not recognize.

This results in This results in agglutinationagglutination, the , the clumping of red blood cellsclumping of red blood cells = = BAD.BAD.

This is why blood types must match.This is why blood types must match.

Blood Blood TypesTypes

AntigenAntigens on the s on the RBCsRBCs

AntibodAntibodies in ies in the the plasmaplasma

Can Can getget blood blood fromfrom

Can Can givegive blood toblood to

AA AA Anti-BAnti-B O, AO, A A, ABA, AB

B B BB Anti-AAnti-A O, BO, B B, ABB, AB

ABAB A and BA and B NoneNone A, B, A, B, AB, OAB, O

ABAB

OO NoneNone Anti-AAnti-A

Anti-BAnti-BOO OO

Problem 1Problem 1

A man has been taken to trial in a paternity A man has been taken to trial in a paternity suit by a woman who claims he is the father suit by a woman who claims he is the father of her son. The man claims innocence. At of her son. The man claims innocence. At the trial the expert witness disclosed the the trial the expert witness disclosed the blood types of all three, as follows:blood types of all three, as follows:– The Woman: Type AThe Woman: Type A– The Man: Type BThe Man: Type B– The Child: Type OThe Child: Type O

Could the man be the father of the child?Could the man be the father of the child?

Problem 1Problem 1 The woman could have the genotype AA or AOThe woman could have the genotype AA or AO The man could have the genotype BB or BOThe man could have the genotype BB or BO If the woman possessed the genotype AO and the If the woman possessed the genotype AO and the

man had BO, then the cross could look like this:man had BO, then the cross could look like this:

Yes, the manYes, the mancouldcould be the father. be the father.However, any manHowever, any manwith type B, A or Owith type B, A or Ocould be the father, so could be the father, so this man cannot be indictedthis man cannot be indicted on this evidence alone. on this evidence alone.

ABAB AOAO

BOBO OOOO

B O

A

O

Problem 2Problem 2

Mr. and Mrs. Jones have just come home Mr. and Mrs. Jones have just come home with their first child, but they are with their first child, but they are disturbed because their friends say that disturbed because their friends say that the baby looks like neither one of them. the baby looks like neither one of them. Have they come home with the wrong Have they come home with the wrong baby? baby?

Mrs. Jones A; Mr. Jones O; Baby Mrs. Jones A; Mr. Jones O; Baby Jones ABJones AB

Problem 2Problem 2

Mrs. Jones could be AA or AOMrs. Jones could be AA or AO Mr. Jones can only be OOMr. Jones can only be OO

Mr. Jones can NOT be the natural father!Mr. Jones can NOT be the natural father! Mrs. Jones could be the mother Mrs. Jones could be the mother

AOAO AOAO

OOOO OOOO

AOAO AOAO

AOAO AOAO

O O

O O

A

A

A

O

Problem 3Problem 3

John and Barry are hiking when Barry John and Barry are hiking when Barry falls down a cliff and severs an falls down a cliff and severs an artery. At the hospital, John offers to artery. At the hospital, John offers to donate his blood for a direct donate his blood for a direct transfusion for Barry. John has type O transfusion for Barry. John has type O blood, and Barry has type AB. Strictly blood, and Barry has type AB. Strictly based on blood type, should the based on blood type, should the hospital accept or refuse John’s hospital accept or refuse John’s offer? Why? offer? Why?

Problem 3Problem 3

Accept.Accept.– John has Type O blood, he is a universal John has Type O blood, he is a universal

donor – he can donate to any other type. donor – he can donate to any other type.

Problem 4Problem 4

John and Barry are hiking again, and John and Barry are hiking again, and this time John falls and gets hurt. this time John falls and gets hurt. Barry offers to return to favor of a Barry offers to return to favor of a blood transfusion at the hospital. blood transfusion at the hospital. Should the offer be accepted or Should the offer be accepted or rejected? Why? rejected? Why?

Problem 4Problem 4

Rejected. Rejected. – Barry has Type AB Blood. Although he can Barry has Type AB Blood. Although he can

receive blood from any other type, he can receive blood from any other type, he can only donate to other people with Type AB. only donate to other people with Type AB.

– John has Type O Blood. Although he can John has Type O Blood. Although he can donate blood to any other type, he can only donate blood to any other type, he can only receive blood from other people with Type receive blood from other people with Type O.O. Otherwise, his anti-A and anti-B antibodies will Otherwise, his anti-A and anti-B antibodies will

attack the A and B anitgens in the blood, leading attack the A and B anitgens in the blood, leading to agglutination. to agglutination.

Biology2008_HumanGenetics.ppt