inheritance 2
TRANSCRIPT
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