1. Red-green colour blindness is caused by an X-linked recessive a s 1z,7)7f ; f:nwmp,pqsxtvkdllele. In the pedigree chart below which individuals must be carpf;mvs: zs )kpqt,x1 7fn,7dw riers of the red-green colour blindness allele?

  2. If the parents in the pedigree chart above had a fe ii y)fep+ wtep2;p4/ourth child who was female, what eie2 )f/ yeipt p+w4p;would be the probability that she was colour blind?

  3. In Labrador dogs, black coat is do f/jnlaalvam*,4p 5-8(paietminant over chocolate coat. The genotype of a black male labrador is unknown. How can,nm*aj/p(e taa-ip5l lv8a4f the genotype of this black Labrador be determined?

  4. Which of the following best def.jz9wju39 3gnmosgw+p dh42p0 t9rirines the term, “gene”?

  5. Phenylketonuria (PKU) is an inherited human disease caused by a recessive aut l3fhjmj)3v n.osomal allele in a gene which codes for an enzyme needed to convert phenylalanine to tyrosine. The PK3jjh.l)3v nf mU 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 theea+yp9)s/ruw z c2a8. w1is mw alleles, yellow or green, is dominant.

ii. Deduce the genotype of the offsarty+ oap sd *f9yfys.)+o/ c1pring.

Iii. Construct a Punnet gri41s l krnq(0r :kybv6bd to show the cross between two offspring plants of the F1 generay6b4k (s rk:l0nqrvb 1tion.

Iv. Deduce the phenotypic ratio for the offspridy;p/y g, /ctjk1 np.png of the F1 cross.

7. Amand has a daughter with Padmavathi. Amand is blood group A, Padmavathiauw,25exp+/fc o smd,x a ehs ,zlx30* is blood group B, and their daughter is blood group O. They are hs +uhso/wf c3 dma0e5xz ,*exx2lpa,, aving 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 interact in a phenot7wm 4 (4jrqveyype to cause the appearancew(rv 4q4my7e j of human skin colour.

a. Deduce genotypes for the three co87 gpzs p -a,zg q4,5x.xjxiywat 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 oaw6p5 wl)jzkoc+)t,shuza) lu:c35 cow in the image.
Use P for the allele for polled and p for the allele for horns.

c. The roan colour, polle josns74(l xwmll7 m8a7iws77d cow in the image is mated with a white coat, horned bullws7(j8l7 amnix7l7s so4w l 7m.
Construct a Punnett square showing all possible phenotypes of the offspring.

10. The pedigree chart shows ABO/j j cbmk;8*vb blood group alleles and their genotype for nail-patella syndrome, an inheri* /jvcmbkb ;j8ted 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.