1. Red-green colour blindness is caused by an X-linked recessive allele. In t l+rnv4o vw6z3v5f3km 1 ugxga1.4sqdhe pedigree chart below which individuals must be carriers of rx 3avn41vwqo16.fglzs3 v5d 4 + mugkthe red-green colour blindness allele?

  2. If the parents in the pedigree chart above had a fourth chi 9qmyn nxz+su ;s1s.zd+fnc:)ld who was female, what would be the probability that szu x;zscs9qs.:)dm y+n+f1n nhe was colour blind?

  3. In Labrador dogs, black coat is dominant pvj n d,o9f;,eover chocolate coat. The genotype of a black male labrador is unknown. How can the genotype ,e,pvojd;f n9of this black Labrador be determined?

  4. Which of the following best definestl+c*ib lai :8 fd1gz6 the term, “gene”?

  5. Phenylketonuria (PKU) is an in gp0 sw1/ :bewg;xiix*herited human disease caused by a recessive autosomal allele in a gene which codes for an enzyme needed to convert phenylalanine to ty wexgb xgi:0/1p*;w sirosine. 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 alleha 6yzx ,tw.+gles, yellow or green, is dominant.

ii. Deduce the genotype of the offspy z1p er(em3hkx q;b47 6fsmwq9 j1is1ring.

Iii. Construct a Punnet grid to show the cross between two offsprxupufp)sar*8 08t j .ting plants of the F1 genet8prf) up 08tx*ua .sjration.

Iv. Deduce the phenotypan6 8m/8satqd ic ratio for the offspring of the F1 cross.

7. Amand has a daughte;ky 2c 6xdsu2m 3n(zlbr with Padmavathi. Amand is blood group A, Padmavathi is blood group B, and their daughter is blood group O. Theyu; lbzc k63y sm2(n2xd 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 inter,n,u ,xui vpn( (+0 2yd74hdajf hoitoact in a phenotype to cauptj+n f4v u(hddxo2nh( u7, ia,,o yi0se the appearance of human skin colour.

a. Deduce genotypes for;pebvd f 8 iy2, d-jp(mr(tzt vk92hw4 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 in the image.8 cfj jeei pa.(hn/3q,wi/4 ri
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 white coat, hshw /cn ot8msn ,+f2f/orned b,c nt/s2hwo8f/nm s+full.
Construct a Punnett square showing all possible phenotypes of the offspring.

10. The pedigree chart shows ABO blood group all)* 8pz okd8o:jlzg-pzeles and their genotype for nail-patella syndrome, an inherited condition. The individuals 1, 3, and 4 in row III are recombinan:zj8g8ldzp)ko- *op z ts. Image by D.B. Pylypiv.

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