Question

Genetic Problems

10. Hemophilia is a sex-linked disorder. A normal woman whose father was hemophiliac marries a man who is not homophiliae What percentage of their son would be would be expected to be hemophiliac? What percentage of their daughters word expected to be hemophiliacs? Again, show your work, using a Punnett Square 11. Given parents with the genotypes AaBbCcDdEe and AaBbccDdEe. what is the probability of them producing offspring with the genotype of AABCDE 12. In humans, widow's peak (W) is dominant over a continuous hairline (w), and gers (F) is dominant over long fingers) Two individuals with widow's peak and shon lingers have a child with continuous hairline and long fingers. What is the genotype o the parents? 13. Mr. and Mrs. Jones have six children Three of them have attached earlobes (recessive) like their father, and the other three have free earlobes (dominant) like their mother. What is the genotype of Mr. Jones? What is the genotype of Mrs. Jones? What are the genotypes of their offspring? 14. In tomatoes, fuzzy skin (F) is dominant over smooth skin (f). A cross between a fuzzy-skinned tomato (parent #1) and a smooth-skinned tomato (parent #2) resulted in 59 fuzzy-skinned tomatoes & 58 smooth-skinned tomatoes. What are the genotypes of the parents? 15. A researcher was breeding identical banded pacooshlas, and found in the offspring a total of 601 banded pacooshlas and 199 pacooshlas without bands. Using appropriate symbols and a Punnett Square, explain these results. 16. Palomino horses are golden in color, but horse breeders have noted that they don't breed true-in other words, palominos bred together don't exclusively produce palominos. In a series of matings among palominos, the following offspring were born: 65 palominos, 32 cream-colored, 34 chestnut (reddish-brown) Explain with symbols and a Punnett Square the pattern of inheritance for this trait. Make sure that you are clear about what genotypes represent what phenotypes. 17. In Cocker Spaniels, black coat color (B) is dominant over red coat color (b), and solid color (S), either solid black or solid red, is dominant over spotted color (S), either black-white or red-white. A solid black male is mated with a solid red female (the parents), and they produce a litter of six pups: 2 solid black pups, 2 solid red pups, 1 black spotted pup, and one red spotted pup. What are the genotypes of the parents? 18. In humans, a gene involved in color vision is located on the X chromosome. The dominant allele (C) is needed for normal color vision, while the recessive allele (C) is responsible for red-green colorblindness.

Answer 1

10) Hemophilia is a sex-linked recessive disease, so if the males are affected they have the mutated allele in their X chromosome, and females inherit their X chromosome from both mother and father, so the daughter of a hemophilic man will have the X chromosome with the mutated allele.

Let the alleles be XH-normal, Xh-hemophilic

the woman has normal vision and her father is affected so her genotype is XHXh and the genotype of the man with normal vision is XHY.

XHXh * XHY

	XH	Xh
XH	XHXH (normal girl)	XHXh ( normal girl)
Y	XHY ( normal boy)	XhY ( hemophilic body)

percentage of affected sons= (number of hemophilic boys/total number of boys)$\times$100

= (1/2)$\times$100

= 50%

here none of the girls are affected so the percentage of affected girls=0%

percentage of sons who are hemophilic =50%

percentage of daughters who are hemophilic =0%