1. Red-green colour blindness is caused by an X-linked recessive 9)qepf6h38 wku+ ok2s7qsx9b. w hzpy allele. In the pedigree chb9e+s7q 2x)6whkpz uhy8pq3owf 9. ks art below which individuals must be carriers of the red-green colour blindness allele?

  2. If the parents in the pedigree chart above had a fourtkgn9b 34gts4r:mzo :x h child who was female, what would be the probability o4ntrgk9bm gx3s: z: 4that she was colour blind?

  3. In Labrador dogs, black coat is dominant over chocolate coat. The genotypepqm+ 9:+evzd9v p,otg5o1p 8)jql wyk of a black male labrtzg)p emj9,981 pol qovw +q+:vd5ykpador is unknown. How can the genotype of this black Labrador be determined?

  4. Which of the foll5 hr5ysda4s r.k 3;jpnowing best defines the term, “gene”?

  5. Phenylketonuria (PKU) is an inherited human disease caused by a rb4 ji1/9 snbpqecessive autosomal allele in a gene which codes f4bpbisj q9n1/ or 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 t /idmk5v:zk( *zbx7yw he alleles, yellow or green, is dominant.

ii. Deduce the genotype of the tv( ttz jm6okq8:,u :poffspring.

Iii. Construct a Punnet grid to show tig9-u(dl26a yl g (zwcmf.:swhe cross between two offspring plants of the F1 (cdgsw fgml2i y l.6u:-9zwa(generation.

Iv. Deduce the phenotypic ratio for the offspring of the 1 dz. v(j/ c2nanj0ityF1 cross.

7. Amand has a daughter with Padmavathi. Amand l(nxf8ory bv1p.h 4/lxa2q7*ba; qvz is blood group A, Padmavathi is blood group B, and their daughter is blood group O. They are having a second4(vaa b8zx7* /hp.2v1 xqbr;n qoflly 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 interac6.:en xuor- oct in a phenotype to cause the appearance of human skin coe-.c xnooru:6lour.

a. Deduce genotypes zw y rqxw-*s9n26iw /ofor 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 imageq90dtafm h:t d -/rxs(.
Use P for the allele for polled and p for the allele for horns.

c. The roan colour, polled cow in the image is mated5cf drmjf l24x1v/m0 zx 8z8jo with a white coat, horned br 1xfzd xjjcmv l85om04/8fz2 ull.
Construct a Punnett square showing all possible phenotypes of the offspring.

10. The pedigree chart shows ABO blood group alleles and their genlc04 m,jbqsz.j.kc /p otype for nail-patella syndrome, an inherited condition. The individuals 1, 3, and 4 in row III are recombinab ,/.ckq.mjjc z 0s4lpnts. Image by D.B. Pylypiv.

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