Question

A maternal effect gene exists in a dominant N (normal)allele and a recessive n (mutant) allele....

A maternal effect gene exists in a dominant N (normal)allele and a recessive n (mutant) allele. How would the results differ in the reciprocal sets of crosses?
nn female x NN male --> F1 --> F2
NN female x nn male --> F1 --> F2

A.) In the first set of crosses, all the F1s would be mutant and all the F2s would be mutant, but in the second set of crosses all the F1s would be normal and all the F2 would be mutant.

B.) In the first set of crosses, all the F1s would be mutant and all the F2s would be normal, but in the second set of crosses all the F1s would be normal and all the F2 would be normal.

C.) In the first set of crosses, all the F1s would be mutant and all the F2s would be normal, but in the second set of crosses all the F1s would be mutant and all the F2 would be mutant.

D.) In the first set of crosses, all the F1s would be mutant, but in the second set of crosses all the F1s would be normal. In both sets of crosses the F2 generation would show a 3:1 ratio of normal:mutant.

Science   Biology   
0 0
Add a commentTranscribed image text
Next >

Homework Answers

Answer #1

Option D is correct) In the first set of crosses, all the F1s would be mutant, but in the second set of crosses all the F1s would be normal. In both sets of crosses the F2 generation would show a 3:1 ratio of

Reason Cross 1.

nn female X NN male

F1 – Nn (All mutant because maternal allele n is mutant)

Nn X Nn

NN, Nn, Nn, nn (3:1 ratio as NN is normal and rest are mutant)

Cross 2: NN female X nn male

Nn F1   (all normal)

Nn X Nn   (Normal as n comes from male)

NN, Nn, Nn, nn (N from females ) 3:1 because of Nn will be mutant

0 0
Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Log In

Sign Up

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
In Drosophila, cut wings are controlled by a recessive sex-linked allele (ct), and fuzzy body is...
In Drosophila, cut wings are controlled by a recessive sex-linked allele (ct), and fuzzy body is controlled by a recessive autosomal allele ( fy). When a fuzzy female is mated with a cut male, all the members of the F1 generation are wild-type. What are the proportions of F2 phenotypes, by sex?
We did a lab about the maternal inheritence in Brassica Rapa- it is uniparental and maternal....
We did a lab about the maternal inheritence in Brassica Rapa- it is uniparental and maternal. so, Cross 1: Varigeated Female x Wild type male: progeny had white, green, and variegated Cross 2: Variegated Male x wild type feamle: progeny all green There is a question that confuses me that i cant answer: 1.)    How would your observations of the F1 generation have differed if the variegation was controlled by a recessive nuclear gene? b. By a dominant nuclear gene?
In Drosophila melanogaster (the common fruit fly), the allele for long, normal wings is dominant over...
In Drosophila melanogaster (the common fruit fly), the allele for long, normal wings is dominant over a recessive allele for short, stubby wings called wingless. What are the expected genotypic and phenotypic ratios expected for the F1 generation for the following cross? Homozygous Long Wings X Heterozygous
1) One parent has yellow flowers, which is the dominant allele Y. The second parent has...
1) One parent has yellow flowers, which is the dominant allele Y. The second parent has white flowers, the recessive allele y. If the offspring are all yellow, what is the genotype of each parent? 2) A plant is homozygous for the recessive gene "a" causing the plant to be short. What is the genotype and the phenotype of this plant? (In your answer, be very clear about which is the genotype and which is the phenotype). 3) The allele...
Grey body, normal bristle, and straight antennae are wild type in fruit flies. Black body, stubble...
Grey body, normal bristle, and straight antennae are wild type in fruit flies. Black body, stubble bristle, and twisted antennae are the corresponding mutant traits for the first isolated mutation in each of the three genes. Grey body, normal bristle, and twisted antennae are dominant. A homozygous dominant female for all three characters is crossed with a recessive male for all three characters to produce an F1 generation that is heterozygous for all three genes. An F1 male is then...
1. In humans, red/green color blindness is sex-linked.  The gene for normal vision (N) is dominant to...
1. In humans, red/green color blindness is sex-linked.  The gene for normal vision (N) is dominant to its recessive allele for color blindness (n). A normal vision woman marries a man with red/green color blindness. Both of their fathers are color blind. What % of their sons would have normal vision? A. 50% B. 75% C. 100% D. 0% 2. The alleles for ABO blood types are designated by IA, IB & i  (also written Io). A woman with type B blood...
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...
You are doing a genetics experiment with fruit flies. In your first cross, you cross two...
You are doing a genetics experiment with fruit flies. In your first cross, you cross two true-breeding flies (P generation). The female parent is brown and wingless and the male parent is black with normal wings. All of the flies in the F1 generation are brown and have normal wings. In the following questions, please indicate the alleles associated with dominant phenotypes by uppercase letters and alleles associated with recessive phenotypes by lowercase letters. Assume the genes are not found...
For problem 1, to compute probabilities, the probability of event 1 AND event 2 is obtained...
For problem 1, to compute probabilities, the probability of event 1 AND event 2 is obtained by multiplying the two probabilities together, whereas the probability of event 1 OR event 2 is obtained by adding the two probabilities. 1. Duchenne muscular dystrophy (DMD) is a condition that causes muscle degeneration and then death. Most people with the condition are wheelchair-bound by age 12 and dead before age 30. The condition is due to a mutation in the gene for a...
"The orange locus in cats is located on the X chromosome. In females, XoXo results in...
"The orange locus in cats is located on the X chromosome. In females, XoXo results in orange cats and X+X+ results in black cats When a female is heterozygous XoX+, they express both colors in patches due to a phenomenon called X-inactivation in which one X in every cell is inactivated. These females are called calico or tortoiseshell, depending on the presence of white spots. Male cats are either orange (XoY) or black (X+Y). A cross between a black female...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT