Station #1: Multiple alleles, blood types (Remember, the possible multiple alleles for blood are written as I A, I B, i, with types A and B being codominant, and O being recessive.) 1. A man with blood type AB has a baby with a woman with blood type O. Show the Punnett square, and list the possible genotype and phenotype ratios of the baby. 2. A woman with blood type A (whose parents both had AB blood) mates with a man with blood type B (his mother was AB and the father was O blood). Show the cross and the genotype and phenotype ratios of their potential offspring
Station #2: Incomplete dominance 3. Colors in chickens follow an incomplete dominance pattern of inheritance. A pair of chickens have chicks which are 15 grey, 6 black and 8 white. What were the genotypes and the phenotypes of the parents? 4. In Four O Clocks, the gene for red flowers (R) is incompletely dominant to the gene for white flowers (W). The heterozygous condition results in pink flowers. Show the results of a cross between a Four O Clock with pink flowers and a Four O Clock with white flowers. What is the probability that the offspring genotype will be RW? What is the probability that the offspring phenotype will be red?
Station #3: Codominance 5. A chicken that has speckled (white with black dots) feathers results when a black chicken is crossed with a white chicken. White chickens breed true; and black chickens breed true. Show the cross between two speckled chickens (use B and W). What is the probability that the chickens will have speckled offspring? What is the probability that the speckled chickens will have white offspring? 6. In guinea pigs, the gene for brown coat (B) is codominant with the gene for cream coat (C). The heterozygous condition results in guinea pigs with patches of brown and cream. If a brown guinea pig and a patchy guinea pigs had babies, what would be the genotype and phenotype ratios of their possible offspring? Draw the Punnett square.
Station #4: Sex-linked traits (Remember, sex-linked traits are written as X LETTER and X letter, and the Y has no superscript.) 7. Hemophilia is a sex-linked recessive condition. A person with hemophilia lacks certain blood clotting proteins. A normal (nonhemophilia) allele is X H, and the recessive hemophilia allele is X h. If a girl is born a hemophiliac, what are the possible genotypes of her parents? 8. Assuming that the above girl s mother is normal with respect to blood clotting, what were the girl s chances of being born with this disease? Show the punnett square.
Station #5: Sex-linked traits (Remember, sex-linked traits are written as X LETTER and X letter, and the Y has no superscript.) 9. In cats, as in people, females are XX and males are XY. Yellow fur is due to the sex-linked gene X B, and black is due to the gene X b. The heterozygous condition X B X b results in a cat with tortoise-shell fur. What kinds of offspring would be expected to result from the cross of a black male with a yellow female? Show the punnett square. 10. What kinds of offspring would be expected to result from the cross of a black male with a tortoise-shell female? Show the punnett square and describe the phenotypes (remember, part of the phenotype is whether it s male or female).
Station #6: Lethal recessive alleles 11. A person who is a carrier for sickle-cell anemia has a baby with another carrier. Show the punnett square of the parents. What is the probability that their child will have the disease? What is the probability that the second child will have the disease? 12. If a child has tay-sachs disease, what are the possible genotypes of his/her parents? Show all possible punnett squares.
Station #7: Multiple alleles, hierarchy (In some cases of multiple alleles, there is a hierarchy of dominance. That is, one allele is dominant to another, which is dominant to the next, etc.) 13. In pigeons, there are three different feather color alleles: B A, B, and b. B A is dominant over all others, and B is dominant over b. Each pigeon can only have two alleles. B A = Ash-red colored feathers B = blue feathers b = chocolate colored feathers List the possible genotypes of an ash-red colored pigeon. 14. When a pigeon with blue feathers is crossed with a pigeon with ashred feathers, some of the offspring have chocolate colored feathers. Show the cross. What is the probability that the two chickens will have an offspring with ash-red colored feathers? What is the probability that they will have an offspring with chocolate colored feathers?
Station #8: Extra credit! 15. Mrs. Smith and Mrs. Jones had babies on the same day in the same hospital. Mrs. Smith brought home a baby girl and named her Sara. Mrs. Jones brought home a baby boy and named him Robert. However, Mrs. Jones was sure that she had had a girl and sued the hospital for the mix-up. Blood tests revealed that Mr. Jones was Type O and Mrs. Jones was Type AB. Mr. And Mrs. Smith were both Type B. Sara was Type A and Robert was Type O. Had a switch occurred? Show the punnett squares. 16. In rabbits, there are four different color alleles for fur color: F = wild type color; dominant to all others F ch = chinchilla color; dominant to C h and c F h = Himalayan color; dominant to c f = albino Each rabbit can have only two alleles. A wild colored rabbit is crosses with an albino, and in all the offspring there is a Himalayan rabbit. Show the cross. What are the genotypes of the parents? What is the probability that they will have an offspring that is Himalayan? What is the probability that they will have an offspring that is albino? What is the probability that they will have an offspring that is wild colored?