1. Red-green colour blindness is caused by an X-linked recessive allele. Iq75edu ldwhgm5a85i f:ht1y, n the pedigree chart below which individuals must be carriers of the red-green colour bl 8 t5qald7 f5u ye,mhh5d:gw1iindness allele?

  2. If the parents in the pedigree chart above had a fourth child who :fvj+axeu- cgbn 45 2rwas female, what would beg jnuvebr2x45 c+-af: the probability that she was colour blind?

  3. In Labrador dogs, black coat is w/uz941a uim91ce gcn dominant over chocolate coat. The genotype of a black male labrador is unknown. Hu9w9/uz1c4nma1ci g eow can the genotype of this black Labrador be determined?

  4. Which of the following best defines the term, “genef8t9p ch rc,7g”?

  5. Phenylketonuria (PKU) is an inherited human dicw 5c)do,8nrd2. nfd wsease caused by a recessive autosomal n ) wf,8cd.5w2dr cdnoallele in a gene which codes for an enzyme needed to 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 or 8oqqnyp;1rs.cj 79qggreen, is dominant.

ii. Deduce the genotype of the (4(wbvtw7 xu:dbk d:soffspring.

Iii. Construct a Punnet grid to show the cross between two offsprii8lk/gkwuz4h2jdesx /d+ z , 7ng plants of the F1+gz/72zdw /8x,uks k4hd jiel generation.

Iv. Deduce the phenotypic ratio for the offspring of the F1 cf(2;sw+ss:bnll zeat* 7 v v7pross.

7. Amand has a daughter with Padmavathi. Amand is blood group A, Pafonz8:axqth 3/(d3hc dmavathi is blood group B, and thx( ohzfd83:q3 hnta/ceir daughter is blood 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 inherita,py* uz,7sbli nce and environmental factors can interact in a phenotype to cause the appea *7up,z ly,bisrance of human skin colour.

a. Deduce genotypes for the e0q-bdobo / ux*v*de(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 in the imag8cphckz+ kl97guzh f*wh2)p , e.
Use P for the allele for polled and p for the allele for horns.

c. The roan colour, polled cow in the image is-j nl u9siw7*r mated with a white coat, horned bul7luwr ij9*-sn l.
Construct a Punnett square showing all possible phenotypes of the offspring.

10. The pedigree chart shows 1jqhpb3):o s96yf xfucx:vjp. 7t+ ag ABO blood group alleles and their genotype for nail-patella syndrome, an inherited condition. The individuals 1, 3, and 4 in row p p9 u)1y3t qsaxvh j+g:6fx.b7oj:fcIII are recombinants. Image by D.B. Pylypiv.

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