In Drosophila, miniature wings (X) result from an X-linked allele that is recessive to the allele for long wings (X). Give the most likely genotypes of the parents in each of the following crosses: Male Parent Female Parent Cross #1 Cross #2 Long Miniature Genotype for male parent #1: Genotype for female parent #1: Genotype for male parent #2: Genotype for female parent #2: Long Long Male Offspring 231 Long 250 Miniature 420 long 417 Miniature Female Offspring 560 Long 0 Miniature 412 Long 415 Miniature Use Xm and X+ for the allele symbols in your answers as there is not a superscript option. Also, remember that males are hemizygous!

Seed color is controlled by 3 independently assorting bi-allelic genes (P, Q, R), such that homozygote pp exhibits recessive epistasis over the seed color pathway, converting a white pigment into yellow, which then becomes orange in the presence of a Q allele, or red in the presence of R. Individuals with both Q and R alleles show pink seeds. In a cross of PpQqRr individuals with ppqqrr individuals, what is the ratio of white-seeds to red seeds? а. 1:4 b. 2:3 с. 1:1 d. 4:1 e. 1:5

In fruit flies, the following X-linked traits are found: white eyes are recessive to red eyes, ebony body is recessive to gray body, and short wings is recessive to long wings.  A cross was made between wild-type males with red eyes, long wings, and gray bodies and females with white eyes, short wings, and ebony bodies.  Female heterozygote resulting from this cross, which had red eyes, long wings, and gray bodies, were then crossed with males with white eyes, short wings, and ebony bodies.  The F2 generation data is obtained below:   1299 white eyes, short wings, ebony bodies 1367 red eyes, long wings, gray bodies 99     white eyes, short wings, gray body 89     red eyes, long wings, ebony bodies 49     white eyes, long wings, ebony bodies 49    red eyes, short wings, gray bodies 1      red eyes, short wings, ebony bodies 1      white eyes, long wings, gray bodies   A) Calculate the map distance separating the three genes B) Which gene is in the middle?

In corn, the genes that determine seed color and coat are both located on chromosome 9.  Seed color (C) can be colored or colorless, where colored seed is dominant and seed coat (W) can be waxy or unwaxy, where waxy is dominant.  A strain that was heterozygous for both genes was crossed with a plant that was homozygous recessive for both genes.  The resulting F1 progeny is described below: colored, waxy seed                17 colored, unwaxy                    33 uncolored, waxy seed           32 uncolored, unwaxy seed       18 The arrangement of alleles in P generation was?

In Drosophila, two genes w and s are X-linked and are 25 map units apart. A heterozygous female fly with a genotype w* s*/ws (w* and s* are wild-type alleles) is crossed to a male wild-type fly. What percent of progeny will have only the wild- type alleles of the w and s genes? O 50% 75% O 12.5% 37.5% 25%

Hemophilia is caused by an X-linked recessive mutation in humans. If a man whose paternal uncle (father's brother) was a hemophiliac marries a woman whose brother is also a hemophiliac, what is the probability that their first child will have hemophilia? (Assume that no other cases of hemophilia exist in the pedigree.) 1/3 0 1/8 0 1/4 1/2

a. In Drosophila, crosses between F1 heterozygotes ofthe form A b / a B always yield the same ratio ofphenotypes in the F2 progeny regardless of the distance between the two genes (assuming completedominance for both autosomal genes). What is thisratio? Would this also be the case if the F1 heterozygotes were A B / a b? (Hint: Remember that inDrosophila, recombination does not take placeduring spermatogenesis.)b. If you intercrossed F1 heterozygotes of the formA b / a B in mice, the phenotypic ratio among the F2progeny would vary with the map distance betweenthe two genes. Is there a simple way to estimate themap distance based on the frequencies of the F2phenotypes, assuming rates of recombination areequal in males and females? Could you estimatemap distances in the same way if the mouse F1heterozygotes were A B / a b?

Miniature wings in Drosophila result from an X-linked allele (w) that is recessive to the allele for long wings (+). In a cross of a long winged male with a long winged female, the following offspring were obtained: 100 long winged males, 106 miniature winged males, and 480 long winged females. Given this result, the female must be a carrier of the miniature wing allele. True False

In Drosophila, the white gene located on the X chromosome affects eye color; an autosomal gene, wingless, is on an autosomal chromosome. Use the following allele symbols: Xw+ _ ,  Xw+Y = wild type red eyes; X-linked dominant allele Xw Xw , XwY = white eyes; X-linked recessive allele Y = Y sex chromosome vg+ = wild type wings; autosomal dominant vg = wingless; autosomal recessive Predict ratios/proportions of genotypes and phenotypes of offspring from the following cross, of a white-eyed male with wild type wings and a wild type red eyed female with wild type wings:  indicate sex of offspring along with phenotypes.                                        XwY vg+ vg             x           Xw+Xw vg+vg

The eye ring color in wood ducks is under the control of a single, sex linked gene.  The dominant allele (R) produces a white eye ring and the recessive allele (r) produces a green eye ring.  Provide the results to the following crosses (note birds have ZZ:ZW sex determination). a)  Provide the phenotypes and phenotypic ratios of a cross between a female with a white eye ring and a male with a green eye ring. b)  Determine the phenotypes and phenotypic ratios for a cross involving an F1 female and an F1 male from the above cross.