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