Question

In: Biology

5. The eye color gene in fruitflies is located on the X chromosome. The dominant wild-type...

5. The eye color gene in fruitflies is located on the X chromosome. The dominant wild-type X^+ allele produces red eyes, while the recessive XW allele produces white eyes. In addition, sex is determined in fruitflies by the ratio of the number of X chromosomes to number of sets of autosomes.

Imagine that a pure-breeding white-eyed female with the genotype X^W X^W Y AA mates with a pure-breeding red-eyed male who has the genotype X^+ Y AA. Imagine that nondisjunction occurs between the females’ X chromosomes during 12% of her meioses. Imagine also that they produce 100 offspring.

What number (not percentages—give me actual numbers out of 100 total offspring) of F1 generation offspring do you expect to have the different possible genotypes and phenotypes this mating pair can produce in their F1 offspring? When you give the phenotypes, give me sex and eye color. If two different genotypes produce the same sex/eye color phenotypes, list the two genotype/phenotype combinations separately. Also, remember that a fruitfly can’t live without an X chromosome. If an individual does not have an X, it dies very early--without its sex being determined (call the phenotype “lethal, no sex”).

Please give an explanation. This is all of the same question, there is no more info given.

Expert Solution

Here in the quistion it is said that non disjunction occurs between female chromosome, thats why the given female drosophila have the genotype of ,(normally female genotype is (for white eyed))

So here we want to perform a cross between (Female) and (male), where + (allele) dominant over w(allele).

So the gametes produced by females contains or and the gametes produced by male have or .

So the progenies formed are , , , and (If no nondisjunction happened in F1).

here red eyed female,

is white eyed male,

is red eyed male,

sex not specified.

so out of 4 offspring red eyed female : white eyed male : red eyed male : sex not specified=1:1:1:1

so in 100 progeny it should be in 25:25:25:25.

[ if nondisjunction happened in X chromosome in female parent, then the gametes formed from the female are

and and the possibel proegenies are , ,and

gladiator answered 2 years ago

In Drosophila the gene for red eyes is dominant over the gene cinnabar eye color, the...

In Drosophila the gene for red eyes is dominant over the gene cinnabar eye color, the gene for gray body color over the genome of the black color of the body, the gene for normal wings – on the genome of rudimentary wings. All the genes are on the same chromosome. After crossing a homozygous female Drosophila with red eyes (cn+), gray body (b+) and normal wings (vg+) with a homozygous recessive male with cinnabar eyes (cn), black body (b)...

In the fruit fly Drosophila melanogaster, wild type eye color is a brick red color and...

In the fruit fly Drosophila melanogaster, wild type eye color is a brick red color and is produced by the action of two genes, one producing red color, the other brown. Vermilion is an X-linked recessive mutation that results in a bright red eye. Brown is an autosomal recessive mutation that results in a brown eye. Flies carrying both the vermilion and brown mutations produce no pigment and have white eyes. True breeding Vermilion eyed females are crossed to brown...

In fruit flies, bristle shape is controlled by an X-linked gene. The dominant wild-type allele (+)...

In fruit flies, bristle shape is controlled by an X-linked gene. The dominant wild-type allele (+) results in normal bristles, while the recessive allele (sn) results in short 'singed' bristles. A normal-bristled female offspring of a male with singed bristles is crossed with a normal-bristled male. If we consider only the progeny that have normal bristles, what is the ratio of females : males among these? 2:3 1:3 3:1 1:1 2:1 3:2 1:2

In flies, eye color is a sex-linked trait. At this locus, the wild-type allele results in...

In flies, eye color is a sex-linked trait. At this locus, the wild-type allele results in red eye color and the mutant results in white eye color. Start with the P generation in which one parent has red eyes and the second parent has white eyes, and discuss offspring and crosses in the F1 and F2 generations in the following two conditions: 1. male with white eyes and female with red eyes; 2. male with red eyes and female with...

Red-green color blindness is caused by a mutation in a gene on the X chromosome. Xa...

Red-green color blindness is caused by a mutation in a gene on the X chromosome. Xa is the recessive mutant allele that causes color blindness; XA is the dominant, functional allele. You meet a patient who has Klinefelter syndrome (that is, he has an XXY karyotype). His mother is color blind, but his father has normal color vision. Your patient has both the XA and the Xa alleles. You hypothesize that your patient’s syndrome is due to a meiotic nondisjunction...

1. In cats, coat color is controlled by a gene on the X chromosome. Yellow coat...

1. In cats, coat color is controlled by a gene on the X chromosome. Yellow coat color is determined by the b allele and black coat color is determined by the B allele. The heterozygous condition results in a color known as tortoise shell. a. What phenotypic ratio of offspring would be expected from a cross between a yellow male and a tortoise-shell female? b. What proportion of the female offspring from a cross between a black female and a...

5. A kidney-bean shaped eye is produced by a recessive gene, k, on the third chromosome...

5. A kidney-bean shaped eye is produced by a recessive gene, k, on the third chromosome of Drosophila. Orange eye color, called cardinal, is produced by the recessive gene cd on the same chromosome. A third recessive gene on chromosome three, e, produces ebony body color. Trihybrid females are testcrossed to produce 4000 progeny, as follows: 1761 kidney, cardinal 1773 ebony 128 cardinal 97 kidney 89 ebony, cardinal 6 kidney, ebony, cardinal 8 wild type 138 kidney, ebony a. Which...

White eye is a recessive X-linked mutant in fruit flies. A wild type male is mated...

White eye is a recessive X-linked mutant in fruit flies. A wild type male is mated to a white-eyed female. What is the probability that an F1 son will be white eyed? A. 0 B. 0.25 C. 0.5 D. 0.75 E. 1.0

1.In fruit flies, eye color is an X-linked trait. Red eyes (XR) are dominant over white...

1.In fruit flies, eye color is an X-linked trait. Red eyes (XR) are dominant over white eyes (Xr)A homozygous dominant female mates with a white-eyed male. What is the phenotypic ratio among males? a.1:0 (all male offspring will have red eyes) b.1:1 (half of the male offspring will have red eyes and half will have white eyes) c.0:1 (all male offspring will have white eyes) 2.In fruit flies, eye color is an X-linked trait. Red eyes (XR) are dominant over...

In humans, brown eye color (B) is dominant over blue (b) while right-handedness (R) is dominant...

In humans, brown eye color (B) is dominant over blue (b) while right-handedness (R) is dominant over left-handedness (r). A brown-eyed, right-handed man marries a blue-eyed, right-handed woman. Their first child is blue-eyed and left-handed. List the genotypes of the parents.