Assignment: Genetics
All work must be shown, Please Box your final answers.
1. From the karyotype sample:
a) Will the child have a genetic disorder? If so, what is the disorder?
b) Explain the reason for your answer.
2. Write out all the gametes produced by a person with the genotype IAIB. Write out the gametes produced by a person who is IBIB. (follow the nomenclature provided). What blood types are possible in the progeny if these two people were to have children?
3. Cystic fibrosis (CF) is inherited as an autosomal recessive trait. Two carriers (heterozygotes) mate.
A) What is the probability that their first child will have CF?
B) Their first child is born and does have CF. The woman gets pregnant a second time. What is the probability that this second child will have the disease?
4. Achondroplasia, a form of dwarfism, is inherited as an autosomal dominant. Two dwarfs, both of whom had one parent of normal height, marry and plan to have a child.
A) What is the probability that their first child will be a dwarf?
B) Their first child is born and is a dwarf. What is the probability that this child is heterozygous?
(HINT: When calculating the probability, only think about the genotypes that are possible.)
5. A dominant gene (H) produces wire-haired texture in dogs; its recessive allele (h) produces smooth hair. A heterozygous female dog is mated with a smooth-haired male dog. What phenotypes are expected in a large number of puppies, and in what ratios?
6. Marion has a baby boy named Ralph. She also claims that Mr. Smith is Ralph's father. Marion is blood type B; Ralph is blood type B; and Mr. Smith is blood type A.
A) Is it possible that Mr. Smith is the dad?
B) If so, what are Ralph's and Mr. Smith's genotypes?
7. A baby has blood type B, Rh+, and the mom has blood type 0, Rh-. Is it possible for a man of blood type AB, Rh- to be the father?
8. Red-green colorblindness is inherited as an X-linked recessive. If a woman is colorblind, but the father of her children is not, what are the chances that her sons will be colorblind?
9. A woman's father has hemophilia (an X-linked recessive trait which results in abnormally long blood clotting times), but she has normal blood clotting, as does her husband.
A) What genotypes are possible among her offspring?
B) What proportion of her sons would be hemophiliac?
C) Construct a pedigree of the original couple (woman with a hemophiliac father marries a normal non hemophiliac man) and their 4 children with all possible outcomes in their ideal percent proportion.