Blood group

• 4 blood groups:

A – allele : AA or AO

B – allele : BB or BO

AB – allele : AB

O – allele :OO ( O recessive)

Blood group inheritance

• If a mother has blood group A and the father has blood group B, what are the blood groups of their children?

Answer

• If the mother is A, the genotype of her blood is AA or AO

• If the father is B, the genotype of her is BB or BO

• Cross between AA and BB = all children will be AB

• Cross between AA and BO = the children will be AO or AB = ?

• ?

If the father has O blood group, and the mother has A, what are the blood groups of their children?

Answer

• Father : O, genotype : OO

• Mother : A, genotype: AO or AA

• Children :– AO X OO = AO and OO– AA X OO = AO and AO

Rhesus factor inheritance

• Rhesus = Rh

• Rh + = has antigen of Rhesus in erythrocyte ( dominant)

• Rh - = no antigen of Rhesus but able to produce antibody if stimulate by antigen. Antibody present in the blood

Rh inheritance

Mother : Rh - ( rh rh) X Father (Rh Rh)

• Foetus : Rh+ Rh-

Rh dominance.

Rhesus inheritance

Rh +

Rh -

Mother; Rh +ve, foetus : Rh -ve

• Mother antigen in RBC unable to diffuse through placenta

• Baby born alive

Rh -

Rh +

If mother Rh –

and foetus is Rh +• During delivery, some of the baby blood in

the placenta mixed with mother blood

• The 1st baby will be born alive

• Rhesus antigen in RBC will enter the mother blood system

• The lymphocyte in the mother system will be stimulated and produce antibody.

• Antibody will remain in mother blood plasma

• In second pregnancy, the Rh + foetus Rh+ in RBC

• Antibody from the mother blood plasma able to diffuse into foetus blood through placenta

• Agglutination occurs in foetus blood

• Causing the premature dead of the foetus

Inheritance of sickle cell anemia

• Caused by recessive allele

• Located on autosome

Thalasemia

Sex inheritance

• Somatic cell has 23 pairs of chromosomes

• 22 pairs are autosomes

• 1 pair is sex chromosome (X and Y)

• Kromosom seks = kromosom X dan Y

• Male:

44 autosome + XY

• Female:

44 autosom + XX

Chromosome in the cell during cell division

Female karyotype ?

• Same as male

• The 23rd pair is XX

Sex inheritance

• How sex of the child is determine?

mother X father

44 + XX 44 + XY

Ovum: 22 + X Sperm: 22 + X or 22 + Y

Child ?

Percentage of chance ?

Child ;

• 44 + XX is a girl

• 44 + XY is a boy

• Percentage of chance:

1/2 girls : 1/2 boys

50 % : 50%

Sex – linkage gene

• Most of the allele that control the disease is:– Recessive – Located in X chromosome

• If two recessive allele pairs up, the disease will appear

• For male, the present of an allele on X is enough to cause the disease.

Heamophilia

Color blindness

Heamophilia

The colour blindness inheritance