1. Red-green colour blindness is caused by an X-linked rececau16 t:r rci1ssive allele. In the pedigree chart below which r 16i: a1rutccindividuals must be carriers of the red-green colour blindness allele?

  2. If the parents in the pedigree chart above hadd qb65 (djvsx)8wl yb4 a fourth child who was female, what would be the probability that she was csq5dw 8x6yjl)vbbd (4olour blind?

  3. In Labrador dogs, black coat is dominant over c bcbp/jk .8rw-si5y 5ghocolate coat. The genotype of a black male labrador is unknown. How can the genotype of tcb5g-y58pr/wk.i bsj his black Labrador be determined?

  4. Which of the following best defines the term, “rb.-nt/ ;pf czgene”?

  5. Phenylketonuria (PKU) is an inherited human disease caused by a reces2h6 vdd:uu r8tsive autosomal allele in a gene which codes for an enzyme needed to convert phenylalanine to tyrosine. The PKU allele produdr26t d:v hu8uces 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 alleles, yellow or green, is domi; jfj ea5bm5 /9lew)menant.

ii. Deduce the genotype of the offsprin1 3k/f.udz -4 kq4z rpua2jnzxg.

Iii. Construct a Punnet grid to show the cross between two offsprfdkb *p.vwae33o nh6 ,ing plants of the F1 gen * eokp,h3 fwn.bv3d6aeration.

Iv. Deduce the phenotypic ratio for the offspring of h08i;tls -uxmbw-/ zvthe F1 cross.

7. Amand has a daughter with Padmavathi. Amand is m0.lf0 avfc/pnfx* uu2kko-4wmve 1.blood group A, Padmavathi is blood group B, and their daughter is blood group O. They are having .2w0-oku*pv x m cmf/4anfvklu0e.1f 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 factorsfisv ::kug3 rt)gmtm: 3aou1 u8+qw f) can interact in a phenotype to cause :+ m:tkvafrugifu3qos 8 tg) :u1 m)w3the appearance of human skin colour.

a. Deduce genotypes for the three coat colour phenotypes in these catl potzpsfbz1p l:+f3k4:k5b p rgd+/5 tle.
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 imagex5) gg3*snrhd q1n mcw fnyd8j5 m/9w8.
Use P for the allele for polled and p for the allele for horns.

c. The roan colour, polled cow in the i-u;ix- d)vn:lj,l- ut4ua bmed4hc7m mage is mated with a white coat, horned bul,:mu-ncxlu4ita -d ) d b;um4ljveh- 7l.
Construct a Punnett square showing all possible phenotypes of the offspring.

10. The pedigree chart shows ABO blood group alleles and their genotype for naedd. x57*yferil-patella syndrome, an inherited condition. e 75ferdy* .xdThe 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.