1. Red-green colour blindness is cauvb-nn44 gsbj 0sed by an X-linked recessive allele. In the pedigree chart below which individuals must be carriers of the red-green colour bl4- n jnb0gv4bsindness allele?

  2. If the parents in ci9pd,w 8wibm8p)k x/the pedigree chart above had a fourth child who was female, what would be the probability that she was colowdb)8k p/i8pcx9mw i,ur blind?

  3. In Labrador dogs, black coat is dominant over chocolate coat. The genotype *2 tpd ;rgg q0s8qep2gof a black male labrador is unknown. How can the ge8pd* 2q;gte2qrgp gs 0notype of this black Labrador be determined?

  4. Which of the following best defines the term, “ge0*cu (dpeh4zi:1l aet ik);na+ n/mrone”?

  5. Phenylketonuria (PKU) is an inherited/*. cgh.qydn -ect:bh zvi80s human disease caused by a recessive autosomal allele in a gene. ndsegc-0y* /ch:vi. ht8bq z 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 allel i sf ;cd8qbp*4w)usm3es, yellow or green, is dominant.

ii. Deduce the genotype of the ofrqiw ,b.) thk/fspring.

Iii. Construct a Punnet grid to show the cj3k. jriqf we; mg(+qa 55xf)oross between two offspring plants of the F1 generation.q .)ak rw5gfxoqfi 3(;5ejjm+

Iv. Deduce the phenotypic ratio for the offsprin1*yv7u*l +i law2bubtg of the F1 cross.

7. Amand has a daughter with Padmavathi. As 2lwhxc a9dd+a,d4n )-auc0m mand is blood group A, Padmavathi is blood group B, and their daughter is blood group O. They are dlwc a0d2x sad),numh 49+c -ahaving 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 fa/0 bd sm ljev):a1llj.ctors can interact in a phenotypeel.1abvd : 0mjll)/js to cause the appearance of human skin colour.

a. Deduce genotypes fh p +2bcz krt7x2p4c.ior 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 imtcu46p )4zkv yage.
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,h(/sd , kcg uk/co1r n,th0w)f horned bullo1kc/ c,,)d(ugk t wn rh/f0hs.
Construct a Punnett square showing all possible phenotypes of the offspring.

10. The pedigree chart shows ABO blood group alleles and theiry5u xr(o7;hc4i-66jorx-k im2j mrek genotype for nail-patella syndrome, an inherited condition. The individuaeir xjc4h k-mu2y rj(6m io75-ko6;rxls 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.