CV system

Ch 10 Blood and Genetics PPT 2

Genetics Vocabulary

Gene- inherited unit, determines traits

Allele- copy of gene

Dominant- allele, capital letter, “A”

Recessive- allele, lower case letter, “a”

Genetics

Homozygous- 2 same alleles, “AA” “aa”

Heterozygous- 2 diff. alleles, “Aa”

Genotype- alleles “AA” “Aa” “aa”

Phenotype- physical expression of genotype

Punnett square- tool to figure out probability of possible offspring

Human ABo Blood Typing

RBC’s contain proteins called antigens (agglutinogens)(Ag) on their surface

Blood type is determined by which Antigen is present on the surface of the RBC

2 Ag’s = A , B

Human ABo Blood Typing

Blood types have proteins called antibodies (agglutinins) (Ab’s) in the plasma opposite of antigens present

2 Ab’s = anti-A , anti-B

Human ABo Blood Typing

Codominance- two alleles equally dominant

Multiple alleles- more than 2 alleles for a gene or trait

3 alleles IA IB both dominant

i (recessive for type O)

Human ABo Blood GroupsBlood type(phenotype) genotypes

______________________________

A IAIA, IAi

B IBIB, IBi

AB IAIB

O ii

Blood types Ag’s present Ab’s present

(phenotype)__________________________________

A A anti-B

B B anti-A

AB A and B none

O None anti-A and anti-B

Ex blood typing problemHeterozygous A woman and homozygous B man have children, what are genotypes and phenotypes of children?

Parents IAi IBIB

Offspring G: 1/2 IAIB and 1/2 IBi

P: 1/2 type AB blood, 1/2 type B blood

Blood Transfusions

Transfusion- transfer of organ or blood from donor to recipient

Universal donor- Type O, no Ag’s, both Ab’s (no antigens for other blood types to recognize

(”its invisible to other blood types)

Universal recipient- Type AB, no Ab’s, both Ag’s (no antibodies to recognize other blood types introduced)

Blood transfusions

Ab’s(antibodies) agglutinate with Ag’s (antigens) if wrong blood type given in a transfusion

Transfusion reaction (bad) = agglutination

Hemolysis of RBC’s

Hemolysis: destruction of RBCs

Rh Blood Typing

Another Ag on surface of RBC = Rh+

Ab (antibodies against it) can be made if negative blood (Rh -) is exposed to/mixed with Rh+ antigen.

The Antibody is called anti-Rh+

2 alleles Rh+ dominant

Rh- recessiveRhesus monkey

Rh Blood typing

Phenotypes genotypes_______________________________+ blood Rh+Rh+

Rh+Rh-

-blood Rh-Rh-

Rh Blood Typing

Blood type Ag present Ab

______________________________

+ Rh+ none

- none can make

anti-Rh+

Rh Blood Typing and HDN

If Rh- blood mixed with Rh+ blood, then person with Rh- blood makes anti-Rh+ against Rh+ blood!...leads to agglutination

When can this occur?

Transfusions and pregnancy

Hemolytic disease of

the newborn

- mom, + dad, + baby

mom makes anti-Rh+

against Rh+ baby’s blood

HDN

mom’s anti-Rh+ will attack next + baby’s blood resulting in HDN

Treatment for HDN

Anti-anti-Rh (anti-Rho) given to mom to bind with her anti-Rh+

instead of it binding to baby’s Rh+ Ag

Ex Rh factor problemHeterozygous + woman and - man have children, what are genotypes and phenotypes of children?

Parents Rh+Rh- Rh-Rh-

Offspring G: 1/2 Rh+Rh-, 1/2 Rh-Rh-

P: 1/2 + blood, 1/2 - blood

Review…so far…

Blood Types? Universal Donor? Universal Recipient? What is agglutination? Why does it occur? Genotypes for Rh +, Rh -? What is HDN? Why does it occur?

Blood Dihybrid ProblemABo and Rh factor

Two traits (Abo AND Rh factor) Need to FOIL

Blood Dihybrid ProblemABo and Rh factor

Homozygous type A, - blood man

Type AB and heterozygous + woman

Parents: (man) IAIARh-Rh- (woman) IAIBRh+Rh-

FOIL…… (man) IARh- IARh- IARh- IARh-

(woman) IARh+ IARh- IBRh+ IBRh-

Dihybrid Problem continued

Offspring

G: 4 IAIARh+Rh-

4 IAIARh-Rh-

4 IAIBRh+Rh-

4 IAIBRh-Rh-

P: 4 A+ 4A- 4AB+ 4 AB-

Sex determination

2 Sex chromosomes : X Y

Genotypes of: (male) XY (female) XX

Sex linkage

Sex linked trait- recessive trait linked to X chromosome (ex. hemophilia)

Ex. hemophilia

___= normal clotting,____= hemophilia

(on X chromosomes only)

Carrier- carries disease but doesn’t express it, usually females

Alleles: XH Xh Y

Sex linked hemophiliaPhenotype genotype

_______________________________

Female, normal XHXH

Female, normal but “carrier” XHXh

Female, hemophiliac XhXh

Male, normal XHY

Male, hemophiliac XhY

Sex linked hemophilia problem

Normal clotting woman and normal clotting male have children some of whom have hemophilia and some of whom are normal, what are genotypes of parents?

Genotypes of parents: XHXh and XHY

Proof: children XHXH, XHY, XHXh- all normal

XhY- hemophiliac