1. Red-green colour blindne k0fvd*c(i2of hg +.k4 fgl,vfss is caused by an X-linked recessive allele. In the pedigree chart below which individuals must be carriers of the red-green colour blindness allele?*v vh,fg40ffkfcgd.+2(ilko

  2. If the parents in the pedigree chart above had a fourth child wh7:/c 2: :nnv0bareqhe;krzjdo was female, what would bbhenq;:2 /jkzr0an: v:ced r 7e the probability that she was colour blind?

  3. In Labrador dogs,6k6 5wm- dttpp3oc)bd black coat is dominant over chocolate coat. The genotype of a black male labrador is unknown. How can the genotype of this blacko6m p 3dp)- 5tbcwdt6k Labrador be determined?

  4. Which of the following best a21jsgvx j*t4defines the term, “gene”?

  5. Phenylketonuria (PKU) is an inheritedr:if9bx )zq d) human disease caused by a recessive autosomal allele in a gene which codes for an enzyme needed to convert phenylalanine to tyrosi )q9d)fb:zirxne. 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 greas3a*p xpg, 7oen, is dominant.

ii. Deduce the genotype of the offsprin+o d8u1p/:zhp op19me ja,i ge nou(5rg.

Iii. Construct a Punnet grid to show the cross between two offspr pbdap2*6tbili v n(3 ;kd7f*ying plants of the F1 generation p*ti;*ya7vd dflip2bk6 b(3n.

Iv. Deduce the phenotypic ratio for the of .du9h 9pnyys8;b wt5nfspring of the F1 cross.

7. Amand has a daughter with Padmavathi. Amand is blood groupyfbo 3-s7/m hmx6 pc.m A, Padmavathi is blood group B, and their daughter is bloosb 3m/hm.6 7fmpoyxc -d group O. 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 environmenzd;b8 /)yc bpttal factors can interact in a phenotype to cause the appearance bc8/y )bp tz;dof human skin colour.

a. Deduce genotypes forx), j42y9 pnwg lpko;t 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 cow y3 fljokgya(r *0i6r. in the image.
Use P for the allele for polled and p for the allele for horns.

c. The roan colour, polled cow in the image is mated with a whit/nbdv8g4pw y. v g7sx sd:fv* v,wa00le coat, horned bulvwa gv:ls*f/v bywd,70p8n dgs40x v.l.
Construct a Punnett square showing all possible phenotypes of the offspring.

10. The pedigree chart shows ABO blood group alleles and their genotype for na+uhh eq 7 im;-z*f, 7goojnkh*il-patella syndrome, an inherited condition. The indivk77f*mn hqhe*h ;uo io -+,gjziduals 1, 3, and 4 in row III are recombinants. Image by D.B. Pylypiv.

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