1. Red-green colour blindness is caused by an X-linked recessive allele. In txn,ztf5 v dl p+vgh+il7bx36;he pedigree chart below which individuals must be carriers of thxzvpi+ hf ntl; dl b5v,+x6g73e red-green colour blindness allele?

  2. If the parents in the pedigree chart above had a fougn5 sjz q;t6wbu ;k)6m:hq7e oi:uki 9qw)1uxrth child who was female, what would bw s6)ohqq;n1i 5j9w k67:e ukz)muiq g:utb x;e the probability that she was colour blind?

  3. In Labrador dogs, black coat i3rpoos.85yi; 0r mjh ps dominant over chocolate coat. The genotype of a black male labrador is unknown. How can the genotyompr;35j. r0o ips8h ype of this black Labrador be determined?

  4. Which of the following best 6qx *tzlot(dmi w9q2; defines the term, “gene”?

  5. Phenylketonuria (PKU) is ar t 9zacn+*2isn inherited human disease caused by a recessive auto ia2t9cz+* snrsomal allele 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 a g2:mll :rr(lklleles, yellow or green, is dominant.

ii. Deduce the genotype of th ls*e6 mcm8s.be offspring.

Iii. Construct a Punnetbpposri2748 o grid to show the cross between two offspring plants of theo7r2 i48sbppo F1 generation.

Iv. Deduce the phenotypic ratio for the offspring of the F1 crossndw5;p hh: az).

7. Amand has a daughter with Padmavathi. Amand ia .96qg5mk j*pjo (yras blood group A, Padmavathi is blood group B, and their drjak p6y9o.qag*5(mjaughter 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 inherit ge/q1 *h boovjmbw5u3l)v7d:ance and environmental factors can interact in a phenotype to cause the appearance of humam *evd :/ ogu1lq)jhbob7wv53n skin colour.

a. Deduce genotypes for the three coat cout+t +dj+,7p gy 8w)j*unjnedlour 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 yt wiy5uf ( t 1u2nm-q-ue975dwxx xw0genotypes of 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 image is mated with a white coat, ho zj.ziu+3c xoa+qe3 k,clb:u7 rned bull. ju37zu lcc+oikxae:., 3bq+z
Construct a Punnett square showing all possible phenotypes of the offspring.

10. The pedigree chart shows ABO blononyhr ) w11 8+niexz8od group alleles and their genotype for nail-patella syndrome, an inherited8zx+)rn1we8 i 1nhny o 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.