You are doing a genetics experiment with Drosophlia melanogaster, the fruit fly. In the "P" generation, you cross 2 true-breeding flies. The female parent is brown and wingless and the male parent is black with normal wings. All the flies in the F1 generation are brown and have normal wings. Assume that the genes are not found on sex chromosomes. Indicate color alleles as "B" for brown, "b" for black, "W" for normal wings, "w" for wingless. (A) What are the genotypes in the P generation? (B) What are the genotypes of the flies in the F1 generation?

You are conducting independent research for your Honors Thesis in a Drosophila research lab.  One of the graduate student researchers has provided you with two mutant strains of Drosophila.  One has scarlet eyes, and the other has brown eyes.  You cross homozygous scarlet-eyed male Drosophila with female flies homozygous for the brown-eye color allele, and all of the male and female F1 flies have wild-type eyes.  Crosses involving F1 males x F1 females yield the results shown below. You know the traits involved are autosomal, and that reciprocal parental crosses produce similar results. A) Please define the alleles represented in this cross.  B) List the genotypes of all classes of individuals in the P, F1, and F2Be sure to use the alleles you defined in Part A Parental (P) Generation Genotype of Homozygous scarlet-eyed males: Genotype of Homozygous brown-eyed females: F1 Generation: Genotype of Wild-type (red-eyed) males and females: F2 Generation: Genotype of wild-type males and…

A farmer who wants to enter the milk industry has purchased a modest venture of 12 heterozygous cows in the herd, all with two dominant cis-linked genes:production of a high volume of milk (+) and a high fertility (+). Recessive alleles (a) and (b), respectively, are present. On chromosome 3, the two genes are 25 cM apart. Bulls owned by two of the farmer's close neighbors are heterozygous for these characteristics as well. The second neighbor's bull has one dominant and one recessive allele from each characteristic on each homolog, but the first neighbor's bull shares the same alleles linked to his cows. 1. What parental genotypes should be crossed if the farmer wants to produce the most calves with high milk output and high fertility? 2. What are the F1 phenotypic frequencies of the cross between the farmer's bull and that of his first neighbor?

In dogs, black coat color (B) is dominant to yellow coat color (b), and straight fur (C) is dominant to curly fur (c). The coat color gene and the fur texture gene are on different chromosomes, so they assort independently, and are not sex-linked. In a cross between two BbCc parents, predict the fraction of offspring with black coat color and straight fur. Give two digits after decimals.

A type of tomato (Solanum lycopersicum) produces fruit in three possible colors: red, green, and orange. You cross a true-breeding orange-fruited plant with a true-breeding green-fruited plant, and all the F1 offspring are red. You intercross the red F1s, and the resulting F2 generation consists of 108 red-, 40 orange-, and 44 green-fruited plants.   1) What type of epistasis is acting (dominant, recessive, duplicate dominant, or duplicate recessive)?    2) Assign the phenotypes to a modified 9:3:3:1 ratio. (Do not just calculate the actual ratio of the phenotypes.)  Red : _____Orange : _____Green: _____

In Drosophila, the allele for long legs (sl*) is wild-type and the allele for short legs (sl) is mutant. The allele for gray body color (b*) is wild-type and the allele for black body color (b') is mutant. The loci for leg length and body color are linked. Flies with sl*sl* b*b* genotypes are mated with flies that have sl s bb genotypes. A testcross was then performed in which the F, offspring with sl*sl b*b genotypes were mated with flies with sl sl. b'b genotypes. The phenotypes of 1000 offspring were recorded. There were 470 flies with long legs and grey body, 30 flies with long legs and black body, 30 flies with short legs and grey body, and 470 flies with short legs and black body. Which of these phenotypes are parental phenotypes? VWhich of these phenotypes are recombinant phenotypes? What is the distance between these two gene loci in centiMorgans (map units)?

A mapping experiment in strawberries shows that the genes for color and plant height are separated by 16cM. In a cross between a heterozygous plant (CcHh) and a homozygous recessive plant, what percent of offspring would inherit a chromosome carrying cH from the heterozygous parent.... 1. if the heterozygous parent’s alleles are in repulsion? _________________ 2. if the heterozygous parent’s alleles are in coupling? _________________

You carry out a trihybrid cross (a cross in which the parental plants differ for three characters)  between a tall pea plant with round, yellow seeds (TT RR YY) and a short pea plant with wrinkled, green seeds (tt rr yy).  The parental plants are homozygous for all of the three characters. They are crossed to produce the F1 generation. Tall, round, and yellow are the dominant traits for each character. What will be the phenotypes of the F1 generation?

Part A) You cross a fly with straight wings with a fly with curved wings to produce the F1 generation, all of which exhibit straight wings. In the F2 generation, you observe 65 straight-winged flies and 16 curved-wing flies. Based upon the results, which phenotype is recessive? Part B) You think this trait is controlled by a single gene, but the F2 numbers don’t quite match a 3:1 expected ratio. Perform a chi-square analysis to determine if the variation you observe is due to chance or not. Based upon this determination, would you keep or reject the “null hypothesis”? Show your work and explain your reasoning.

In the following cross, imagine that you have a female fly that has two Xs and one Y due to a nondisjunction event in her mother's germ cells. Draw out what the possible gametes are for both the female and the male and also a Punnett square showing the genotypes, phenotypes, and sex of the possible flies as a result of this cross. You do not need to provide the probabilities of each of these. Red-eyed wi C Ở Red-eyed wt XX Y X Y Meiosis