1. Red-green colour blindness is caused by an X-linked recessive allele. In b5wo mv: ook4i5qkv 5 833gwvtthe pedigree chart beloww5v3bvtg: 4w 5mkovi3 o5ko 8q which individuals must be carriers of the red-green colour blindness allele?

  2. If the parents ine3ypj1mc,o (ho 8 9ush the pedigree chart above had a fourth child who was female, what w 8(, cuph hy1semo39joould be the probability that she was colour blind?

  3. In Labrador dogs, blacky7ywi f: pmtitop 6t i5u742yj5lb13 k coat is dominant over chocolate coat. The genotype of a black male labrador is unkno2ft:iiw y37i y74t 6y5tokjm5p1pbulwn. How can the genotype of this black Labrador be determined?

  4. Which of the following p* g9lm g z9i9sphz4ky*2f:lmbest defines the term, “gene”?

  5. Phenylketonuria (PKU) is an inherited hu9 bjvw;kk66pt man disease caused by a recessive autosomal allele in a gene which codes for an enzyme needed tvk6kwt6;j b9po convert phenylalanine to tyrosine. 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 o4l.-m i 2imrzdr green, is dominant.

ii. Deduce the genotype of the ox/jh8 ) 1wprhcffspring.

Iii. Construct a Punnet grid to show the cross between two offspgy:7 -2jvccuqi5 hn ;xring plants of the F1 generat:n ;q7xhgc iy5jcv-2uion.

Iv. Deduce the phenotypic ratio for the offspring of the F1 crv3pvqk 69stjxt -6:t2cj 0aqv oss.

7. Amand has a daughter witf6 si ;fzil*d 10griej*k.c0wlpo8s2h Padmavathi. Amand is blood group A, Padmavathi is blood group B, and their daughter is blood g0dprlg1s 6w 8si;o.*cj0l ei ifz*k2froup 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 environmental factors cau9a r6fhz : f;wc2otn5n interact in a phenotype to cause the appearance of human skin colour.f 5a o2htf:6zwu;nr9c

a. Deduce genotypes for the thre-mg n bbtnszye i/a 39f9p(d-/e 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) ((km0p.f)w fa alyre genotypes of the cow 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 matedkmv.pz(kt uwc2k 6/8 g with a white coat, horned bul z 8wu(tk/ p.gc2mvk6kl.
Construct a Punnett square showing all possible phenotypes of the offspring.

10. The pedigree chart shows ABO blood group alleles and their g)vhj m hf:l,5denotype for nail-patella syndrome, an inherited condition. The indivivj,l:m5)d hf hduals 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.