Question

10. Red green colorblindness is an X-linked recessive disease. That means that it is carried on the X chromosome, so men have just one copy of the gene while women have two. In women, both copies must be the recessive disease allele in order to show the disease phenotype, but because men only have one allele, just one recessive allele causes the disease phenotype. Matt and Kate both have normal vision, but Kate's father is colorblind. Use X for the colorblindness allele. 2. What is Matt's genotype? Kate's genotype? Don't forget that this condition is X-linked. b. What percentage of their children would you predict will be colorblind? What is the chance that they will have a colorblind daughter? Show your work with a Punnett square. 11. Tongue rolling is an autosomal dominant trait. That means that it is carried on an autosomal chromosome and that it only takes one dominant disease allele to cause the disease phenotype. Individuals without the disease have both normal recessive alleles. George can roll his tongue but his mother can't roll her tongue George's wife Elaine cannot roll her tongue, either. Use the letter d for the alleles. a. What is George's genotype? Elaine's genotype? b. What percentage of their children would you predict will be tongue rollers? Show your work with a Punnett square.

Answer 1

Xry XX -O 10 KATE IMATTI XY xxe a normal copy. 2 @ For Kate (a female) to be have normal vision would mean that she should either have a normal x chromosomes or be a heterozygote ( 1 wormal l 1 recessive, disease associated allele since she has a colourblind father he is bound to transfer the disease associated allele to kate. Hence the x-chromosome should be contributed by her mother On the other hand, Matt being have even a in the should have a hakmal X-chromosome single coptohething disease associated alle Genotype of kate = Genotype of Matt = xy a male cannot afford to xxe b 오 Х xe XX Normal xxe Х Nonnal xry (carrier) Х Normal % of children being colourblind = No. of colourblind 100 Total colourblind als There is no chance to have a colourblind daughter, because she would need two recessive disease - associated allele Cone from each parent. Since her father matt has no atendea recessive allele to contribute & hence daughters would either be homozygous normal or carriers but never colourblind x100= 4

Ca aa AA or Aa ПЯЕТІЯАя George Elaine да aa @ since George can roll his tongue he should alleast have 1 dominant allele. Now since his mother can't roll, the contribut a regessi Courozygous recessive and could be able to for his parents father to contribute a dominant allele. . George is a heterozygote Elaine, being -tongue roller, would be have to be a homozygous recessive. Genotype of George = Aa Genotype of Elaine - aa a non- b A f a slias Aa Aa 2% of tongue rollers Tongue Tongue = No. of ta' x 100 a normal Total Normal x 100 = 50% fraller rouler aa aa LU 2 4 TAO