1. Red-green colour blindness is c mzf3q 4 suu05yv2ax9kaused by an X-linked recessive allele. In the pedigree chart below which individuals must be carrie4maxfzksy 5qv3u90u 2rs of the red-green colour blindness allele?

  2. If the parents in the pedigree chart above had a fourth child who was femaleb5 i j8vl,nhq)a wnt-:, what would be the q8j wah b-):i ,n5nvltprobability that she was colour blind?

  3. In Labrador dogs, black coat is dominant over chocolate coat. The g- j 4:mr,os.n tcf0yedenotype of a black male labrador is unknown. How can the genotype of this black Labrador oefr-nc tms j.y:,04dbe determined?

  4. Which of the following best defines the term, “gene4)gvl.,hab tu 5ui+kj ”?

  5. Phenylketonuria (PKU) is an inherj bn( 02-hu+sk plh5kvited human disease caused by a recessive autosomal allele in a gene which codes for an enzyme needed to (kjp hv sl5u h0-2nbk+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 -(lk6fwmc4ve ie ui24 alleles, yellow or green, is dominant.

ii. Deduce the genotype of the offspri3bpfub3y/ jgpsjf 1h5i (/ m(kng.

Iii. Construct a Punnet grid to show the cross between two offspring p pee /4:yzxt;clants of the F1:ez/ctp ex4y ; generation.

Iv. Deduce the phenotypic ratio for the offsprictv td748,tvq ng of the F1 cross.

7. Amand has a daughter with Padmavathi. Amand is blood s 1c,07y5pg apv j*cqlgroup A, Padmavathi is blood group B, and their daughter is blood group O7 j 0p5,1qcas vglcp*y. 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 inheri;5)hg,i0q u;e y v8 ipomgz9m*ea e)ectance and environmental factors can interact in a phenotype to cause the appearance of humv ;oi5mq8,e 9e;)ci)myha* eggp0 eu zan skin colour.

a. Deduce genotypes for the three coat colourffw e1z wmwm5/f: ork m./k8)d 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 genotyponqx fb,91uj2ene l,1 +/ecbqes 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 a5bmpzep u+:6im.ba:ws;aog7 l zk0: y white coat, horned bul+. 7:azzmbmeiyl k:ba :650g uswp;op l.
Construct a Punnett square showing all possible phenotypes of the offspring.

10. The pedigree chat*lh7z )rsjz* 2h9daprt shows ABO blood group alleles and their genotype for nail-patella syndrome, an inherited condition.zjh*z*pld r9 )s7 2tha 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.