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

Solutions

Expert Solution

Answer:

The female progeny of an affected father has normal phenotype (is normal bristled) indicating she is a carrier as the X-linked allele from father codes for short singed bristles and X-linked allele from normal mother codes for normal bristles.

This female when crossed with normal bristled male will produce following cross:

Hence we conclude that the probability of
Normal bristled male = 1/4 or 25%
Normal bristled female = 1/4 or 25%

Therefore, ratio of Normal bristled male : Normal bristled female = 1 : 1

gladiator answered 1 year ago

Next > < Previous

Related Solutions

Three genes in fruit flies affect a particular trait, and one dominant allele of each gene...

Three genes in fruit flies affect a particular trait, and one dominant allele of each gene is necessary to get a wild-type phenotype. What phenotypic ratios would you predict among the progeny if you crossed triply heterozygous flies? Multiple Choice 27:64 9:23 37:64 1:3 27:37 3:5 1:7 Would the answer be 27:37 wild to mutant?

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...

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...

Brachydactyly is a condition caused by an allele dominant to wild-type in humans, in which the...

Brachydactyly is a condition caused by an allele dominant to wild-type in humans, in which the fingers and toes are shortened. In a population of 10,000 people, 1,600 are BB, 4,800 are Bb, and 3,600 are bb. A)What percentage of people in this population have short fingers and toes? B)What is the frequency of the b allele? C)Is this population in Hardy-Weinberg equilibrium?

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...

Question text In drosophila (fruit flies): The yellow gene is on the X-chromosome, the gene product...

Question text In drosophila (fruit flies): The yellow gene is on the X-chromosome, the gene product plays a role in body colour. Wild type flies are a light brown/tan in colour, homozygote yellow mutants have a more yellow shaded body colour. We'll use y+ to represent the wild type allele, and y to represent the mutant allele. y+ is dominant to y. The vestigial gene is on chromosome 2. Homozygote vestigial mutants have very short wings, and cannot fly. We'll...

Purebred lines of fruit flies with wild type (tan) body color and stubby bristles are mated...

Purebred lines of fruit flies with wild type (tan) body color and stubby bristles are mated to flies with ebony bodies and normal bristles. The resulting F1 offspring all have a normal wild-type body color and stubby bristles. The F1 flies are crossed with flies recessive for both traits (i.e. ebony bodies and normal bristles). a. What phenotypes and ratios of phenotypes would you expect to find among the offspring produced by crossing the F1 with flies recessive for both...

The allele b gives Drosophila flies a black body, and b+ gives brown, the wild-type phenotype....

The allele b gives Drosophila flies a black body, and b+ gives brown, the wild-type phenotype. The allele wx of a separate gene gives waxy wings, and wx+ gives nonwaxy, the wild-type phenotype. The allele cn of a third gene gives cinnabar eyes, and cn+ gives red, the wild-type phenotype. A female heterozygous for these three genes is testcrossed, and 2,424 progeny (you could also use n=2,423) are classified as follows: cn+ · wx+ · b 101 cn · wx+...

Imagine that you as a fruit fly researcher cross true breeding, wild-type flies to true breeding,...

Imagine that you as a fruit fly researcher cross true breeding, wild-type flies to true breeding, eyeless flies in the P generation. The resulting F1 generation is made up of 100% wild-type flies with normal eyes. Based on Mendelian genetics, what phenotype ratio would you expect to see for a F1 monohybrid cross? How would you go about determining the genotype ratio in the F2 generation? In cactus, the relationship between Gene S and Gene N is known to be...

Long wings in fruit flies are dominant to vestigial wings. A long winged fruit fly is...

Long wings in fruit flies are dominant to vestigial wings. A long winged fruit fly is crossed with a vestigial winged fly. What are the genotypes of the parents and offspring if the cross results in 72 long winged and 68 vestigial winged offspring.

Subjects