In Drosophila, the gene eyeless (ey) is on the fourth chromosome, and four wings (fw) and legs for antennae (lfa) are both on the third chromosome 20 cM apart. Consider that mutations in all three genes each cause recessive phenotypes. What frequencies would you expect for the various phenotypes amongst the offspring of the test cross shown below (note that the comma separates alleles on the same chromosome, and the semicolon separates different chromosomes):

Vermilion eye color in Drosophila is sex-linked and recessive. What would be the phenotypes of maleand female progenies of a cross between a 6 vermilion female and 6 wild-type (red) male.  what is the f1 and f2 generation. if a reciprocal cross is done containing 6 WT females with 6 mutant males what is the F1 and F2 generation. Do they contain the single gene or double gene?

Because of non-disjunction in some stocks of Drosophila. melanogaster, about 1 in 65,000 egg cells have two copies of the X chromosome and about 1 in 375 egg cells have no X chromosome. Assuming that meiosis in males is ‘always normal', what is the expected frequency of XXX females and XO males arising from any number of fertilized eggs? Do not be concerned as to whether it is lethal or not.

Two genes, m (apical meristem) and r (starburst rhizosomes), are linked on chromosome #5 in pea plants. Both genes are recessive to wild type and found to be 8 MU apart. If a wild type heterozygote is test- crossed, and produces 91 apical meristem plants and 8 apical, starburst plants from a total of 200 plants were produced, how many wild type plants will be produced? 4 8. 12 16

Give typed explanation  In pea plants, the tall allele (T) is dominant to the dwarf allele (t) and the yellow pea color allele (Y) is dominant to the green pea color allele (y). Cross TtYy with Ttyy. What would be the genotype and phenotype ratios in their offspring? (Please include the gametes produced by each parent.)

In Drosophila, the genes st (scarlet eyes), ss (spineless bris- tles), and e (ebony body) are located on chromosome 3, with map positions as indicated: st SS e 44 58 70 Each of these mutations is recessive to its wild-type allele (st*, dark red eyes; ss*, smooth bristles; e*, gray body). Phenotypically wild-type females with the genotype st ss e*/st* st* ss+ e were crossed with triply recessive males. Predict the phenotypes of the progeny and the frequen- cies with which they will occur assuming (a) no interfer- ence and (b) complete interference.

The data set attached summarizes F2 numbers from an F1 cross arising from two, true-breeding Drosophila strains (P generation), which differ with respect to two mutant traits. Here are the hypothesis: Leg length - The wild-type and mutant alleles for leg length are incomplete dominant relative to each other. Justification: The data set includes three phenotypic categories for leg length: wild type (long leg), medium leg, and truncated wings. The presence of three distinct phenotypes suggests an incomplete dominance pattern, where the heterozygous individuals exhibit an intermediate leg length phenotype (medium leg). The absence of purebred short-legged individuals supports the idea that the long leg allele is dominant over the short leg allele. This shows that mode of inheritance is incomplete dominance of the alleles relative to each other. Since the data does not mention any specific differences between males and females, we can assume that the mode of inheritance for the trait is…

A cross was performed using Drosophila melanogaster involving a female known to be heterozygous for both ebony body and sepia eyes and a male known to be homozygous wild type male. The resulting progeny were allowed to mate with one another to produce the data set. Three repetitions of the experiment were conducted. The following data were produced from the crosses. Test these data to determine if they are significantly different from the expected phenotypic ratio. Use the 5% level of significance.  Your answer should include the hypothesized cross in genotypes, the Chi-squared value, the critical value and whether you reject or do not reject for each experiment. Wild eye Wild body – 112, Wild eye Ebony body – 40, Sepia eye Wild body – 35, Sepia eye Ebony body – 11

In DrosophilaI, yellow body (y), crossveinless (cv), and forked bristles (f) are all found in the X chromosome, in that order. Yellow is 14 map units from crossveinless, and crossveinlessis 32 map units from forked. A yellow, forked female is crossed to a crossveinless male. An F1 female is crossed to a yelow, crossveinless, forked male, yielding the F2 generation. In the F2, what is the probability of obtaining progeny that express crossveinless and forked, but not yellow? Assume a coefficient of coincidence of 1.  In the F2, what is the probability of obtaining progeny that are completely wild type? In the F2, what is the probability of obtaining progeny that express crossveinless, but not yellow or forked?