11) Two syntenic genes, B and C, are located 25 cM apart in Drosophila. You cross a ccDD female fly to a male CCdd fly to produce F1 progeny. Next, you select an F1 female and perform a test cross. What proportion of the F2 progeny are expected to be ccDd? a) 12.5% b) 37.5% c) 25% d) 75% e) 50%

In a cross between a white-eyed female (ww) and a red-eyed male (w+Y), nearly all the progeny were either red-eyed females (w+w) or white-eyed males (wY). However, about 1 in every 2000 F1 flies had an "exceptional phenotype" and was either a white-eyed female or red-eyed male. How did Bridges explain this unexpected result? A) Crossing over B) Incomplete cytokinesis C) Incorrect synapsis D) Nondisjunction E) Pseudoautosomal region

Two pure-breeding mutant plants produce white flowers. When they are crossed, all of the progeny have wild-type purple flowers. What does this genetic complementation tell you? A) The genes are part of two distinct biosynthetic pathways. B) The two lines exhibit different mutations in the same gene. C) More than one gene is involved in determining the phenotype. D) The allele is pleiotropic. E) The allele exhibits incomplete dominance.

In a testcross of a female Drosophila heterozygous for 3 linked, recessive genes the following phenotypes were observed and used to make a map of these genes.  Calculate the interference.  A---(3.0)---D-----(4.8)-----B A) There is negative interference. B) 1.44 C) 2.08 D) 1 E) 0

A female from true breeding line of Drosophila with white eyes is crossed with a male from a true breeding line with brown eyes. All of the offspring have wild type brick red eyes. Which of the following explanations is most likely?   A) There are many alleles for the single gene for eye color. Wild type brick red eyes result only when the fly is heterozygous. B) The alleles for brown, white, and brick red eyes are alleles for a single locus. The allele for brown eye color is dominant to the allele for brick red eye color and to the allele for white eyes. C) There is more than one gene for eye color. The brown mutation and the white mutation occur in separate genes and are both recessive to the wild type alleles.  The offspring are heterozygous for both genes, so they are phenotypically wild type. D) None of the above. It is not possible for a cross between a white-eyed and a brown-eyed fly to produce wild type offspring.

Females from a pure-breeding curly-winged strain are mated with males from a pure-breeding straight-winged (wild-type) strain. The F1 mate with each other to produce an F2 generation that consists of 160 flies with curly wings and 80 with straight wings. What can you infer from this observation? Explain your answer and why the other options do not qualify,  A) Curly wings is a recessive trait.  B) The dominant curly wing allele is also a recessive lethal.  C) Wing shape is controlled by two codominant alleles.  D) Two interacting genes determine wing shape.  E) All of the hybrid F 1 flies had straight wings.

Two plants with white flowers, each from true-breeding strains, were crossed. All the F1 plants had red flowers. When these F1 plants were intercrossed, they produced an F2 consisting of 177 plants with red flowers and 142 with white flowers. (a) Propose an explanation for the inheritance of flower color in this plant species. (b) Propose a biochemical pathway for flower pigmentation and indicate which genes control which steps in this pathway.

You cross two yeast strains one is an ade auxotroph the other is a pro auxotroph and allow the diploid to sporulate. When you score each spore in the ascus you find the following proportions: 518 PD, 8 NPD, and 225 T. a.) What are the genotypes of each spore in all three types of the tetrads. b) Are these genes linked why or why not? c.) If these genes are unlinked what would you expect the progeny numbers and ratios to be? d.) What is the formula to determine the most accurate distance between these genes? If linked what is the map distance?

In snapdragons, red flower color (R) is incompletely dominant over white flower color (r). The hybrids or heterozygous plants (Rr) are pink in color.  a) Show the genotype for a white flower and for a red flower. b) If a red-flowered plant is crossed with a white-flowered plant, what are the genotypes and phenotypes of the F1 generation plants?  c) What genotypes and phenotypes will be produced in the F2 generation?  d) How did the genotypic and phenotypic ratio compare to each other in this incomplete dominance cross? e) What would the phenotypic ratio have been if this had been complete dominance? f) What kind of offspring can be produced if a red-flowered plant is crossed with a pink-flowered plant?  g) What kind of offspring is/are produced if a pink-flowered plant is crossed with a white-flowered plant?

In tomato the mutant genes o (oblate=flattened fruit), p (peach=hairy fruit) and s (compound inflorescence) were found to be in chromosome 2. The test cross results are: 73 110 + 348 2 2 + 306 p 96 63 a) Construct the linkage map b) What are the genotypes of the homozygous parents used in making the F1 heterozygote? c) Compute for the coefficient of coincidence. O o O O +