2. 356 Q7. Haemophiliacs possess a non-functional form of the gene responsible for the production of blood clotting factors. Shown below is the occurrence of haemophilia in one family. Completed forms to be made available for external moderation. 4. = male = female = male haemophiliac 8. 1. 5. 6 3. 4. 11 12 Using the following symbols: H= dominant allele h = recessive allele 1) State the genotypes of the following individuals. Individual Genotype 1. HH ЧАН HH 9. 6. 2) On the basis of the information provided, is the inheritance of haemophilia: 1) autosomal or sex-linked? Sex-linked (ii) dominant or recessive? Recessive 3) State the probability of individual 8 being a carrier of haemophilia. Individual 8 is a female and is a daughter of individual 1 and 2. Individual 1 x individual 2 支 chis location. XHXh x XHY HX XHXH normal female SHXh normal but carrier female HX Completed forms to be made available for external moderation. 4. AHX normal male Haemophilic male Ihus the probability that individual 8 is a carrier is 50%. 4) Explain why only females can be carriers of haemophilia. Haemophilia is a sex linked recessive disease suggesting that only females can be carrier and not males because females carry two X chromosomes and males carry only one X chromosome. The mutation in this disease occurs in the X chromosome. As the recessive character is only expressed when both the Alleles in a gene are mutated so females usually do not suffer with the disease but they can be carriers that is in them one allele is normal which is dominant and one allele is recessive which is abnormal but in males there is only one X chromosome and if it is mutated then he would be suffering from the disease and if it is not then he would be normal. So no carriers for male. Q8. (1) Complete the following genetic diagram to show how parents who did not suffer from haemophilia, could have a son wit h haemophilia but also other children who did not suffer from haemophilia. Phenotype of parents Genotype of parents Genotype of gametes Normal male Normal female Genotype of offspring Phenotype of offspring What is the probability of the couple having a daughter with haemophilia? (1) What is the probability of the couple having another son with haemophilia? (1) MacBook Pro