Solution-Trait coding for blood type | Homework Helpers

1. NO PUNNETT SQUARE NECESSARY: Just map out your reasoning and put a box around your final an What is/are the possible blood type(s) (i.e, phenotypes) of the father if a woman with type A has a daughter with type AB blood?

2. In aIDition to the trait coding for blood type A, B or O, there is another gene that codes for the blood “Rh factor” that determines whether a person has a “+” or “-” blood phenotype for this trait. Two alleles are possible, Rh+ and Rh-, and the Rh+ allele is dominant to the Rh- allele. QUESTION: If the mother of a child has a blood phenotype of O+, and her child is A-, list all possible blood phenotype(s) the father could be for both blood traits. (Again, use no Punnett squares: just map out your reasoning and put a box around your final answer.

3. Let’s say that gender determination in Tasmanian devils is caused by the same type of X-Y system as in humans. There are two possible alleles for the gene for eye shape, which is a gene that is linked to the X chromosome: the allele for beady little eyes is dominant to the allele for round, soulful eyes. A female with beady little eyes is mated with a male with round, soulful eyes and some of their sons also have soulful eyes just like dad.(a) Please write the Punnett Square showing the cross between the two parents with respect to the trait in question.(b) What is the phenotypic ratio of all possible offspring that result from this cross?

4. (a) What are the chances that a couple with normal blood-clotting ability will have a daughter who has hemophilia, if their first child was a hemophiliac son? You are expected to know without being told that blood-clotting ability, like color vision, is an X-linked trait. (please show all math) Punnett Square:ANSWER: _______________(b) For the same parents as in (a), what are the chances that the next three children these same parents have will be twodaughters without hemophilia followed by a hemophiliac son? (please show all math)ANSWER: ________________-page 2-

5. A mother who has Type A+ blood and a man who has Type B- blood already have a child with Type O-blood. What is the probability that this man and woman will have an O+ son or an A- daughter? (From the info given, you should be able to determine the parents’ genotypes; then please show BOTH Punnett squares and math calculations)