1. Red-green colour blindness is caused by an X-linke:qjk0/oer,ph d recessive allele. In the pedigree chart below which individuals must be carriers of the red-green co,e rp/qkh:oj0 lour blindness allele?

  2. If the parents in the pedigree chart above had a fourth child who was fet2r2gi( q4kaa9 j ua1 repq;6smale, what wou aar1 (4rj qgut;2qap9iks6 2eld be the probability that she was colour blind?

  3. In Labrador dogs, black coat is dominant over chocolate coat. The genotbbg ;oz/iwpd-2 0vxb3ype of a blac- 0bw/23vbpzd; o ixbgk male labrador is unknown. How can the genotype of this black Labrador be determined?

  4. Which of the following best defines the td2s75 :tih ynl-v rre1erm, “gene”?

  5. Phenylketonuria (PKU) is an inherited hrf a3.4hm;f xrp4 )rvquman disease caused by a recessive autosomal allele in a gene which codes for an enzyme needed trf4a rvq43; mrpxh).fo 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 al: p6wkz9 inaznow4 0/sleles, yellow or green, is dominant.

ii. Deduce the genotype o;lwwhi8g8 r me6h* c3wf the offspring.

Iii. Construct a Punnet grid to show the cross betw/xf, k )2foy4wzogz 3yeen two offspring plants of the F1 4o)fo,wxy /zz3f yg2kgeneration.

Iv. Deduce the phenotypic ratio for the offspring of the F3bnf)f;e jq67iog,oecg p: n-1 cross.

7. Amand has a daughter with Padmavathi. Amand is blood group A, Padmavatrd af4,oze lu0n)g j,oigkzj *9+1 uz:hi is blood group B, and their daugk4:f dj)o 9 eziglj1,a0uzor*z+g,nu hter 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 inheritance and envirdtw2uo(bofu,7 4 4o y-undvq/onmental factors can interact in a phenotype 4 (2u ov,du-oyd obqt4nu7wf/to cause the appearance of human skin colour.

a. Deduce genotypes for the tdp1;9pjy,59 sg lskiyhree 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 j ew3z z 734vvs-kt.btof 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 oji s5bfze vu5k(; u62(f .zf:yj t:.lcurof)image is mated with a white coat, horned bullu5jj(5tu virzkfzo.c2(ou y l;.bf: s fe)f6 :.
Construct a Punnett square showing all possible phenotypes of the offspring.

10. The pedigree cha0aseo yp6es q; ;az*o4 xt)t1ftamv1+rt shows ABO blood group alleles and their genotype for nail-patella syndrome, an inherited condition. The individuals 1, 3, and 4 in row III are recombytpat1+; tee) 6so0 mvszx 1*fq 4o;aainants. Image by D.B. Pylypiv.

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