1. Red-green colour blindness7 w c8sfmill9+tef(9y is caused by an X-linked recessive allele. In the pedigree chart below which individuals must be carriers of the red-green 9s7 f +ecllf(9my8twicolour blindness allele?

  2. If the parents in the pedigree chart above had a fourth chi/u7e fn2g exdz2j5l214wewrwld who was female, what would be the probability that she was colour dew2f217ze j4 wl52r/ genxwublind?

  3. In Labrador dogs, black coat is dom:wz58r1kpgj b g.e .jhinant over chocolate coat. The genotype of a black male labrador is unknown. How .h : zjk5bgr81wepg.jcan the genotype of this black Labrador be determined?

  4. Which of the following 0 (znlcsx t 8: a(ivr7fowv8 i,ht2 ar2t7mic2best defines the term, “gene”?

  5. Phenylketonuria (PKU) is an inherited human disease caused by a recessive aup 3;lxi n4a w0mhk6xd*3mguh(tosomal allele in a gene which codes for an enzyme needed to convert phenylalanine to tyrosine. The PKU allele produces a non-functional enzyme. ;0mw6 *ghxa4 pmn(lhux3k d3i
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, yel:l8ear:3.wtij: p zjg low or green, is dominant.

ii. Deduce the genotype of tbx,4dva k an(7: 9x d/qg/ighvhe offspring.

Iii. Construct a Punnet grid to show t2- k2f(kqgex8:hh nyihe cross between two offspring plants of the F1 generatio 8f 2:hqikgx-e2nh( kyn.

Iv. Deduce the phenotypic ratio for the)- ali (mjl/qx y)u2xw offspring of the F1 cross.

7. Amand has a daughter with Padmavathi. Amand is blood group A, Pad9c)/zs kquft0mavathi is blood group B, and their daughter is blood gro z)qusf9 /t0ckup 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 can in559ujybtxm 8ba8;ggh teract in a phenotype to cause the appearance of human skin55 g u8tj;bbhma 9gx8y colour.

a. Deduce genotypes for the three coat colo*e y ziwd1x 7h,obwkx/z:(:j abxlej*/:lt* vur 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 imsht:scu. ve60age.
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 wljbe 0:kx rg-bxlnn-/;* i9ltuz 4j-zith a white coat, horned bul:0x lxu ;-enjnigjzt rb49blkz--/ l* l.
Construct a Punnett square showing all possible phenotypes of the offspring.

10. The pedigree chart shows ABO b5ax f3 42p5r t*-p0oy rgctzfklood group alleles and their genotype for nail-patella syndrome, a52potkpczf f43yx-g05 rt*ar n inherited condition. The individuals 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.