1. Red-green colour blindness le:txz: qsl z3)s73 aofu k73xis caused by an X-linked recessive allele. In the pedigree chauslf77ks3eqtz la 3:) x:zo 3xrt below which individuals must be carriers of the red-green colour blindness allele?

  2. If the parents in the pedigr4s -/ ac3kodneee chart above had a fourth child who was female, what would be the probability that she was colour oek3 san cd-4/blind?

  3. In Labrador dogs, black coat is dominant over chocolate coat. The g /kbnm+ti i5z.ml *fy)enotype of a black male labrador is unknown. How can yifbk)/i.*l 5nzt+ mmthe genotype of this black Labrador be determined?

  4. Which of the following best 0v8 ewj:0qk ..dp j.tn4eprjydefines the term, “gene”?

  5. Phenylketonuria (PKU) is an inhe 3dyth5bm5g-9iuj+ tzrited human disease caused by a recessive autosomal allele in a gene which codes for an enzyme needed to convert phenylalanine to tyg9-tji5b u ztyd3mh5+rosine. The PKU allele produces a non-functional enzyme.
Which of the following statements are correct?
I. Two parents heterozygous for the condition could have a child with PKU.
II. If the mother of the child is homozygous and not affected by PKU, her children will not be affected.
III. The polypeptide sequence of the enzyme of an affected person is identical to a person without the condition.
IV. Two parents who are not affected with PKU cannot have a child with the disorder.

I. Identify which of the alleles, yellow or green, is d gcvv5 7 )wx-nvsuf(-cominant.

ii. Deduce the genotyz423h akariru)r(amn 9-zb l. m+f z-npe of the offspring.

Iii. Construct a Punnet grid to show the cross between two offspring plants ofv.h rp/favnc5f22 -xu the F1 gecu fnr2f5.2 /av xvp-hneration.

Iv. Deduce the phenotypic ratio for the offspring z7eupm,ivzh4o / 3qs bg(u42 wof the F1 cross.

7. Amand has a daughter with Padmavathi.pvm 4urqv57 mm6cql+rim 9.6r Amand is blood group A, Padmavathi is blood group B, and their daughter is blood group O.vmrl .6rv5 mq7riq46+9mcmup They are having a second child, a son.
Deduce the probability that their unborn son will be blood group O. Explain your working.

8. Explain how inheritance and environmental factors can interact in a phenot,: gz2ujdvyezv179 2;ddq/2l r kqe ffype to ca:zf9u 22jlgvq2d y;/dz e,17dker fqvuse the appearance of human skin colour.

a. Deduce genotypes br5k8zr,kv / vy sqzk.ocl)w9 6- eoa-for the three coat colour phenotypes in these cattle.
Use the symbols $C^W$ for the white coat allele, and $C^R$for red coat allele.

b. Deduce the parental genotypes of the coj5q ua umyy.)ra-c5 vs xe197bw in the image.
Use P for the allele for polled and p for the allele for horns.

c. The roan colour, pom *i7bwtls*e/ b* x(n (sqtqy,7e9xenlled cow in the image is mated with a white coat, horned bull. bstlbn wn7t(*ye/,9m* x q7q*ee(ixs
Construct a Punnett square showing all possible phenotypes of the offspring.

10. The pedigree chart shows ABO blood group alleles and their genotype fo- 96i1itjva vbr nail-patella syndrome, an inherited condition. The individuals 1j bvv6-9 i1tia, 3, and 4 in row III are recombinants. Image by D.B. Pylypiv.

Use the pedigree chart to explain the meaning of gene linkage.